Parasiticidal compositions comprising eprinomectin and praziquantel, methods and uses thereof

ABSTRACT

This invention relates to compositions for combating ectoparasites and endoparasites in animals, comprising eprinomectin and praziquantel in combination with a pharmaceutically acceptable carrier, and optionally an antioxidant. This invention also provides for an improved methods for eradicating, controlling, and preventing parasite infections and infestations in an animal comprising administering the compositions of the invention to the animal in need thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application No. 62/627,978, filed Feb. 8, 2018, and U.S. Provisional Application No. 62/697,576, filed Jul. 13, 2018, both of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention provides veterinary compositions having a stable, extended shelf-life, the compositions comprise at least one macrocyclic lactone active agent and at least one anthelmintic active agent for controlling ectoparasites and endoparasites in animals; the use of these compositions against ectoparasites and/or endoparasites, and methods for preventing or treating parasitic infections and infestations in animals.

BACKGROUND OF THE INVENTION

Animals such as mammals and birds are often susceptible to parasite infestations/infections. These parasites may be ectoparasites, such as insects, and endoparasites such as filariae and other worms. Domesticated animals, such as cats and dogs, are often infested with one or more of the following ectoparasites:

-   -   fleas (e.g. Ctenocephalides spp., such as Ctenocephalides felis         and the like),     -   ticks (e.g. Rhipicephalus spp., Ixodes spp., Dermacentor spp.,         Amblyoma spp., and the like),     -   mites (e.g. Demodex spp., Sarcoptes spp., Otodectes spp., and         the like),     -   lice (e.g. Trichodectes spp., Cheyletiella spp., Lignonathus         spp. and the like),     -   mosquitoes (Aedes spp., Culux spp., Anopheles spp. and the like)         and     -   flies (Hematobia spp., Musca spp., Stomoxys spp., Dematobia         spp., Coclyomia spp. and the like).

Fleas are a particular problem because not only do they adversely affect the health of the animal or human, but they also cause a great deal of psychological stress. Moreover, fleas are also vectors of pathogenic agents in animals and humans, such as dog tapeworm (Dipylidium caninum).

Similarly, ticks are also harmful to the physical and psychological health of the animal or human. However, the most serious problem associated with ticks is that they are the vector of pathogenic agents in both humans and animals. Major diseases which are caused by ticks include borrelioses (Lyme disease caused by Borrelia burgdorferi), babesioses (or piroplasmoses caused by Babesia spp.) and rickettsioses (also known as Rocky Mountain spotted fever). Ticks also release toxins which cause inflammation or paralysis in the host. Occasionally, these toxins are fatal to the host.

Likewise, farm animals are also susceptible to parasite infestations. For example, cattle are affected by a large number of parasites. A parasite which is very prevalent among farm animals is the tick genus Boophilus, especially those of the species microplus (cattle tick), decoloratus and annulatus. Ticks, such as Boophilus microplus, are particularly difficult to control because they live in the pasture where farm animals graze.

Animals and humans also suffer from endoparasitical infections including, for example, helminthiasis which is most frequently caused by a group of parasitic worms categorized as cestodes (tapeworm), nematodes (roundworm) and trematodes (flatworm or flukes). These parasites adversely affect the nutrition of the animal and cause severe economic losses in pigs, sheep, horses, and cattle as well as affecting domestic animals and poultry. Other parasites which occur in the gastrointestinal tract of animals and humans include Ancylostoma, Necator, Ascaris, Strongyloides, Trichinella, Capillaria, Toxocara, Toxascaris, Trichiris, Enterobius and parasites which are found in the blood or other tissues and organs such as filarial worms and the extra intestinal stages of Strogyloides, Toxocara and Trichinella

Milbemycin or avermectin derivatives are natural or semi-synthetic compounds that contain a 16-membered macrocyclic ring. The avermectin and milbemycin series of compounds are potent anthelmintic and antiparasitic agents against a wide range of internal and external parasites. The natural product avermectins are disclosed in U.S. Pat. No. 4,310,519 to Albers-Schonberg, et al., and the 22, 23-dihydro-avermectin compounds are disclosed in Chabala, et al., U.S. Pat. No. 4,199,569. For a general discussion of avermectins, which include a discussion of their uses in humans and animals, see “Ivermectin and Abamectin,” W. C. Campbell, ed., Springer-Verlag, New York (1989). Naturally occurring milbemycins are described in Aoki et al., U.S. Pat. No. 3,950,360.

Eprinomectin is a semi-synthetic compound of the avermectin family and consists of a mixture of isomeric compounds, isomer B1a (4″-epi-acetylamino-4″-deoxy-avermectin B1a) and isomer B1b (4″-epi-acetylamino-4″-deoxy-avermectin B1b), which differ by a single methylene group. The B1a and B1b isomers have the following structures:

Eprinomectin is used for effective control of internal parasites in cattle and other ruminant species (deer, goats). In the United States, eprinomectic is approved by the FDA for the use in beef and dairy cattle, including lactating dairy cattle (IVOMEC® EPRINEX® Pour-On for Beef and Dairy Cattle).

Eprinomectin, like other avermectins, binds selectively and with high affinity to glutamate-gated chloride ion channels which occur in invertebrate nerve and muscle cells. This leads to an increase in the permeability of the cell membrane to chloride ions with hyperpolarization of the nerve or muscle cell, resulting in paralysis and death of the parasite.

Other pharmaceutical or therapeutic agents are those known in the art to treat parasitic infection caused by nematodes and trematodes. In order to treat cestode (and trematode) infections in warm-blooded animals, it is known, to administer 2-acyl-4-oxo-pyrazino-isoquinoline derivatives to the animal (see, e.g., U.S. Pat. No. 4,001,441, herein incorporated by reference). A compound of this class that is often used to treat cestode and nematode infections is praziquantel, which has the following structure:

Praziquantel may be used in the treatment of endoparasitic infections including infections by liver flukes or schistosoma. Praziquantel works by causing severe spasms and paralysis of the worm's muscles.

U.S. Pat. No. 9,173,403 B1 relates to compositions for combating ectoparasites and endoparasites in animals, comprising at least one 1-arypyrazole, at least one macrocyclic lactone, at least one insect growth regulator, and at least one anthelmintic compound in combination with a pharmaceutically acceptable carrier.

U.S. Pat. No. 6,991,801 B1 provides for topical anthelmintic formulations which comprise a pharmaceutically active combination consisting of at least one macrocyclic compound and at least one compound selected from the group consisting of praziquantel, morantel and pyrantel, which are dissolved in a non-aqueous solvent or solvent mixture, and optionally a thickening agent.

Notwithstanding the compositions comprising milbemycin or avermectin active agents alone or in combination with other active agents described in the documents above, there is a need for veterinary compositions and methods with improved efficacy and spectrum of coverage and increased shelf life to protect animals against both endoparasites and ectoparasites.

INCORPORATION BY REFERENCE

Any foregoing applications, and all documents cited therein or during their prosecution (“application cited documents”) and all documents cited or referenced in the application cited documents, and all documents cited or referenced herein (“herein cited documents”), and all documents cited or referenced in herein cited documents, together with any manufacturer's instructions, descriptions, product specifications, and product sheets for any products mentioned herein or in any document incorporated by reference herein, are hereby incorporated herein by reference, and may be employed in the practice of the invention.

Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.

SUMMARY OF THE INVENTION

The present invention provides compositions and formulations comprising at least one macrocyclic lactone compound in combination with at least one anthelmintic compound; uses or veterinary uses thereof for the treatment or prophylaxis of parasitic infections and infestations of animals (either wild or domesticated), including livestock and companion animals such as cats, dogs, horses, chickens, sheep, goats, pigs, turkeys and cattle, with the aim of ridding these hosts of parasites commonly encountered by such animals. In an embodiments, the topical veterinary composition of the invention are advantageously in the form of a spot-on or a pour-on formulation for application to localized areas on the animal to be treated (e.g. in one spot on the midline of the neck, between the base of the skull and the shoulder blades for spot-on or in line down the back from the shoulders to the tail for pour-on). In another embodiment, the topical veterinary composition has a shelf-life of at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months.

The invention also provides methods for the treatment or prevention of parasitic infections and infestations in animals, comprising administering an effective amount of a composition described herein. Surprisingly, it has been found that the inventive compositions and formulations described herein have a stable, extended shelf-life and exhibit superior broad spectrum efficacy against harmful endoparasites and/or ectoparasites over a long duration compared to compositions known in the art.

In one embodiment, the invention provides topical veterinary compositions having an extended shelf-life comprising effective amounts of at least one macrocyclic lactone active agent and at least one anthelmintic active agent together with a pharmaceutically or veterinarily acceptable liquid carrier, and optionally an antioxidant, wherein the composition has a shelf-life of at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months. In another embodiment, the composition further comprises a penetration enhancer, optionally wherein the penetration enhancer is propylene glycol.

In some embodiments, the macrocyclic lactone active agent is an avermectin or a milbemycin active agent including, but not limited to, eprinomectin, ivermectin, selamectin, milbemectin, milbemycin D, milbemycin oxime, or moxidectin.

In other embodiments, the compositions and methods comprise at least one of thiabendazole, oxibendazole, mebendazole, fenbendazole, oxfendazole, albendazole, triclabendazole, febantel, levamisole, pyrantel, morantel, praziquantel, closantel, clorsulon, an amino acetonitrile active agent, or an aryloazol-2-yl cyanoethylamino active agent.

In some embodiments, the topical veterinary composition of the invention may comprise a C₁-C₁₀ alcohol or ester, a C₁₀-C₁₈ saturated fatty acid or esters, a C₁₀-C₁₈ monounsaturated fatty acid or ester, a monoester or diester of an aliphatic diacid, a glycerol monoesters, a glycerol diester, a glycerol triester, a glycol, a glycol ether, a glycol ester, a glycol carbonate, a polyethylene glycol, a polyethylene glycol monoether, a polyethylene glycol diether, a polyethylene glycol monoester, a polyethylene glycol diester, or a mixture thereof as components in the pharmaceutically or veterinarily acceptable carrier or diluent. In other embodiments, the compositions may include acetone, acetonitrile, benzyl alcohol, ethanol, isopropanol, diisobutyl adipate, diisopropyl adipate, glycerol formal, butyl diglycol, dipropylene glycol n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, liquid polyoxyethylene glycols, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dimethyl isosorbide, 2-pyrrolidone, N-methylpyrrolidone, diethylene glycol monoethyl ether, triacetin, butyl acetate, octyl acetate, propylene carbonate, butylene carbonate, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, or any combination thereof in the pharmaceutically or veterinarily acceptable carrier or diluent. In other embodiments, the topical veterinay composition of the invention comprises glycerol formal and dimethyl isosorbide (DMI). In an embodiment, the glycerol formal is unstabilized due to the absence of stabilizers. In another embodiment, the glycerol formal is unstabilized due to the absence of ethylenediaminetetraacetic acid (EDTA). In another embodiment, the glycerol formal is unstabilized due to the absence of 2,6-di-tert-butyl-4-methyl phenol.

In some embodiments, the topical veterinary composition of the invention comprises an antioxidant. In other embodiments, the antioxidant is butylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA).

In an embodiment, the macrocyclic lactone active agent comprises eprinomectin. In another embodiment, the anthelmintic active agent comprises praziquantel.

The present invention provides a topical veterinary composition having a stable, extended shelf-life, the composition comprises about 0.01% (w/v) to about 10% (w/v) eprinomectin, about 1.0% (w/v) to about 30.0% (w/v) praziquantel, about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 2.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists essentially of about 0.01% (w/v) to about 10% (w/v) eprinomectin, about 1.0% (w/v) to about 30.0% (w/v) praziquantel, about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 2.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists essentially of about 0.1% (w/v) to about 5.0% (w/v) eprinomectin, about 5.0% (w/v) to about 15.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists essentially of about 0.1% (w/v) to about 1.0% (w/v) eprinomectin, about 8.0% (w/v) to about 12.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists essentially of about 0.40% (w/v) eprinomectin, about 8.30% (w/v) praziquantel, about 0.10% (w/v) butylated hydroxytoluene, about 30.38% (w/v) unstabilized glycerol formal, and QS dimethyl isosorbide.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists of about 0.01% (w/v) to about 10% (w/v) eprinomectin, about 1.0% (w/v) to about 30.0% (w/v) praziquantel, about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 2.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists of about 0.1% (w/v) to about 5.0% (w/v) eprinomectin, about 5.0% (w/v) to about 15.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists of about 0.1% (w/v) to about 1.0% (w/v) eprinomectin, about 8.0% (w/v) to about 12.0% (w/v) praziquantel, about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal, about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide, and about 0.01% (w/v) to about 1.0% (w/v) butylated hydroxytoluene.

The present invention provides a topical veterinary composition having an extended shelf-life, the composition consists of about 0.40% (w/v) eprinomectin, about 8.30% (w/v) praziquantel, about 0.10% (w/v) butylated hydroxytoluene, about 30.38% (w/v) unstabilized glycerol formal, and QS dimethyl isosorbide.

In some embodiment, the topical veterinary composition having an extended shelf-life of the present invention is in the form of a spot-on or a pour-on formulation.

The present invention provides a method for the treatment or prevention of a parasitic infestation or infection in an animal comprising administering to the animal in need thereof an effective amount of any of the topical veterinary compositions described herein. In some embodiment, the parasite is an ectoparasite or an endoparasite.

It is an object of the invention to not encompass within the invention any previously known product, process of making the product, or method of using the product such that the Applicants reserve the right and hereby disclose a disclaimer of any previously known product, process, or method. It is further noted that the invention does not intend to encompass within the scope of the invention any product, process, or making of the product or method of using the product, which does not meet the written description and enablement requirements of the USPTO (35 U.S.C. § 112, first paragraph) or the EPO (Article 83 of the EPC), such that Applicants reserve the right and hereby disclose a disclaimer of any previously described product, process of making the product, or method of using the product.

These and other embodiments are disclosed or are obvious from and encompassed by, the following Detailed Description.

BRIEF DESCRIPTION OF THE FIGURES

The following detailed description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may best be understood in conjunction with the accompanying drawings, in which:

FIG. 1 is a plot showing the concentration (ng/mL) of eprinomectin and praziquantel in the blood of cats over time (days) after administration of the formulation in Example 1 to cats.

DETAILED DESCRIPTION

The present invention provides novel and inventive compositions comprising at least one macrocyclic lactone compound in combination with at least one anthelmintic compound together with a pharmaceutically acceptable carrier or diluent, optionally an antioxidant. In some embodiments, the compositions further comprise a penetration enhancer.

The compositions of the present invention have an extended shelf-life, e.g., at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months.

The compositions of the invention can be in a variety of forms suitable for different forms of administration including, but are not limited to, oral formulations, injectable formulations, and topical, dermal or subdermal formulations.

In some embodiments of the invention, the compositions are in a form that is suitable for topical administration, which includes spot-on formulations that are applied to a localized area on an animal. Topical pour-on formulations are also encompassed by the invention. These formulations provide surprisingly effective protection of the animals against endoparasites for an extended period of time.

In one aspect, the invention provides topical compositions comprising at least one macrocyclic lactone compound in combination with at least one anthelmintic compound together with a pharmaceutically acceptable carrier or diluent, optionally an antioxidant and/or a penetration enhancer.

In one embodiment, the compositions of the invention comprise at least one avermectin or milbemycin compound. In another embodiment, the at least one avermectin or milbemycin compound included in the compositions is abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, selamectin, milbemectin, milbemycin D, moxidectin or nemadectin. In yet another embodiment, the compositions of the invention comprise eprinomectin.

In one embodiment, the compositions of the invention comprise at least one anthelmintic compound. In another embodiment, the compositions of the invention comprise praziquantel.

Also provided are methods and uses for the treatment and/or prophylaxis of parasitic infections and infestations of animals, comprising administering an effective amount of a formulation of the invention described herein to the animal.

The invention includes at least the following features:

(a) The invention provides novel compositions having a stable, extended shelf-life that exhibit superior activity against animal parasites comprising at least one macrocyclic lactone compound in combination with at least one anthelmintic active agent, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(b) topical veterinary formulations having a stable, extended shelf-life that exhibit superior activity against animal parasites comprising at least one macrocyclic lactone active agent in combination with at least one anthelmintic compound, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(c) veterinary compositions having a stable, extended shelf-life comprising eprinomectin in combination with at least one anthelmintic compound, or pharmaceutically acceptable salts, solvates or hydrates thereof, and a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(d) veterinary compositions having a stable, extended shelf-life comprising or consisting essential of eprinomectin in combination with praziquantel, or pharmaceutically acceptable salts, solvates or hydrates thereof, and a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(e) topical spot-on veterinary formulations having a stable, extended shelf-life, consisting essentially of eprinomectin and at least one anthelmintic compound, or pharmaceutically acceptable salts, solvates or hydrates thereof, and a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(f) methods for the treatment or prevention of parasitic infections and infestations in an animal comprising administering an effective amount of a composition having a stable, extended shelf-life, the composition comprises at least one macrocyclic lactone active agent in combination with at least one anthelmintic active agent, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(g) methods for the treatment or prevention of parasitic infections and infestations in an animal comprising administering an effective amount of a composition having a stable, extended shelf-life, the composition comprises, consists essentially of, or consists of eprinomectin in combination with praziquantel, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant;

(h) use of veterinary compositions having a stable, extended shelf-life, the compositions comprise at least one macrocyclic lactone active agent in combination with at least one anthelmintic compound, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent in the prevention or treatment of animal parasites;

(i) use of veterinary compositions having a stable, extended shelf-life, the compositions comprise, consist essentially of, or consist of eprinomectin in combination with praziquantel, or pharmaceutically acceptable salts, solvates or hydrates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant.

In this disclosure and in the claims, terms such as “comprises,” “comprising,” “containing” and “having” and the like can have the meaning ascribed to them in U.S. patent law and can mean “includes,” “including,” and the like; “consisting essentially of” or “consists essentially” likewise has the meaning ascribed in U.S. patent law and the term is open-ended, allowing for the presence of more than that which is recited so long as basic or novel characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments; and “consist of” likewise has the meaning ascribed in U.S. patent law and excludes any element, step, or ingredient not specified in the claim.

It is also noted that in this disclosure and in the claims and/or paragraphs, the compounds of the invention are intended to include all stereoisomers and crystalline forms (which includes hydrated forms, polymorphic forms and amorphous forms with up to 15% by weight crystalline structure) thereof.

Definitions

Terms used herein will have their customary meaning in the art unless specified otherwise. The organic moieties mentioned in the definitions of the variables of formula (I) or (IA) are—like the term halogen—collective terms for individual listings of the individual group members. The prefix C_(n)-C_(m) indicates in each case the possible number of carbon atoms in the group.

The term “animal” is used herein to include all mammals, birds and fish and also include all vertebrate animals, including humans. Animals include, but are not limited to, humans, cats, dogs, cattle, chickens, cows, deer, goats, horses, llamas, pigs, sheep and yaks. It also includes an individual animal in all stages of development, including embryonic and fetal stages.

The term “effective amount” as used herein means a concentration of the active agents in the composition sufficient to elicit the desired biological response to the target parasite(s) after administration of the composition to the animal, as measured by methods known in the art and/or described in the examples herein. In some embodiments, an “effective amount” of the active agents in the composition will provide an efficacy of at least 70% against the target parasite compared to an untreated control. In other embodiments, “an effective amount” of the active agent will provide an efficacy of at least 80%, or at least 85% compared to untreated controls. More typically, “an effective amount” of the active agents will provide an efficacy of at least 90%, at least 93%, at least 95% or at least 97% against the target parasite.

In a specific embodiment, the term “about” or “approximately” means within 20%, preferably within 10%, and more preferably within 5% of a given value or range.

Stereoisomers and Polymorphic Forms

It will be appreciated by those of skill in the art that certain compounds within the compositions of the invention may exist and be isolated as optically active and racemic forms. Compounds having one or more chiral centers, including at a sulfur atom, may be present as single enantiomers or diastereomers or as mixtures of enantiomers and/or diastereomers. For example, it is well known in the art that sulfoxide compounds may be optically active and may exist as single enantiomers or racemic mixtures. In addition, compounds within the compositions of the invention may include one or more chiral centers, which results in a theoretical number of optically active isomers. Where compounds within the compositions of the invention include n chiral centers, the compounds may comprise up to 2^(n) optical isomers. The present invention encompasses the specific enantiomers or diastereomers of each compound as well as mixtures of different enantiomers and/or diastereomers of the compounds of the invention that possess the useful properties described herein. The optically active forms can be prepared by, for example, resolution of the racemic forms by selective crystallization techniques, by synthesis from optically active precursors, by chiral synthesis, by chromatographic separation using a chiral stationary phase or by enzymatic resolution.

The compounds within the compositions of present invention may also be present in different solid forms such as different crystalline forms or in the form of an amorphous solid. The present invention encompasses different crystalline forms as well as amorphous forms of the inventive compounds.

In addition, the compounds within the compositions of the invention may exist as hydrates or solvates, in which a certain stoichiometric amount of water or a solvent is associated with the molecule in the crystalline form. The compositions of the invention may include hydrates and solvates of the active agents.

Salts

Also contemplated within the scope of the invention are acid or base salts, where applicable, of the compounds of the invention provided for herein.

The term “acid” contemplates all pharmaceutically acceptable inorganic or organic acids. Inorganic acids include mineral acids such as hydrohalic acids such as hydrobromic acid and hydrochloric acid, sulfuric acid, phosphoric acids and nitric acid. Organic acids include all pharmaceutically acceptable aliphatic, alicyclic and aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids and fatty acids. In one embodiment of the acids, the acids are straight chain or branched, saturated or unsaturated C₁-C₂₀ aliphatic carboxylic acids, which are optionally substituted by halogen or by hydroxyl groups, or C₆-C₁₂ aromatic carboxylic acids. Examples of such acids are carbonic acid, formic acid, acetic acid, propionic acid, isopropionic acid, valeric acid, α-hydroxy acids such as glycolic acid and lactic acid, chloroacetic acid, benzoic acid, methane sulfonic acid, and salicylic acid. Examples of dicarboxylic acids include oxalic acid, malic acid, succinic acid, tartaric acid, fumaric acid, and maleic acid. An example of a tricarboxylic acid is citric acid. Fatty acids include all pharmaceutically acceptable saturated or unsaturated aliphatic or aromatic carboxylic acids having 4 to 24 carbon atoms. Examples include butyric acid, isobutyric acid, sec-butyric acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and phenylsteric acid. Other acids include gluconic acid, glycoheptonic acid and lactobionic acid.

The term “base” contemplates all pharmaceutically acceptable inorganic or organic bases, including hydroxides, carbonates or bicarbonates of alkali metal or alkaline earth metals. Salts formed with such bases include, for example, the alkali metal and alkaline earth metal salts, including, but not limited to, as the lithium, sodium, potassium, magnesium or calcium salts. Salts formed with organic bases include the common hydrocarbon and heterocyclic amine salts, which include, for example, ammonium salts (NH4⁺), alkyl- and dialkylammonium salts, and salts of cyclic amines such as the morpholine and piperidine salts.

In one embodiment, the invention provides compositions that comprise at least one macrocyclic lactone active agent in combination with at least one anthelmintic compound, or pharmaceutically acceptable salts, hydrates or solvates thereof, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer.

In an embodiment, the invention provides compositions (e.g., spot-on, pour-on) having an extended shelf-life for the treatment or prevention of a parasitic infection or infestation in an animal comprising at least one macrocyclic lactone active agent in combination with at least one anthelmintic compound together with a pharmaceutically acceptable carrier, wherein the macrocyclic lactone active agent is eprinomectin.

The macrocyclic lactone compounds are also well known in the art and can be obtained commercially or through known synthesis techniques. For avermectins, ivermectin and abamectin, reference may be made, for example, to the publication “Ivermectin and Abamectin”, 1989, by M. H. Fischer and H. Mrozik, William C. Campbell, published by Springer Verlag., “Macrocyclic Lactones in Antiparasitic Therapy”, 2002, by J Vercruysse and RS Rew published by CABI Publishing or Albers-Schonberg et al. (1981), “Avermectins Structure Determination”, J. Am. Chem. Soc., 103, 4216-4221. For doramectin, “Veterinary Parasitology”, vol. 49, No. 1, July 1993, 5-15 may be consulted. For milbemycins, reference may be made, inter alia, to Davies H. G. et al., 1986, “Avermectins and Milbemycins”, Nat. Prod. Rep., 3, 87-121, Mrozik H. et al., 1983, Synthesis of Milbemycins from Avermectins, Tetrahedron Lett., 24, 5333-5336, U.S. Pat. No. 4,134,973 and EP 0 677 054, all of which are incorporated herein by reference.

Macrocyclic lactones are either natural products or are semi-synthetic derivatives thereof. The structures of the avermectins and milbemycins are closely related, e.g., by sharing a complex 16-membered macrocyclic lactone ring; milbemycins lack the glycosidic moiety of the avermectins. The natural products avermectins are disclosed in U.S. Pat. No. 4,310,519 to Albers-Schonberg et al., and the 22,23-dihydro avermectin compounds are disclosed in Chabala et al., U.S. Pat. No. 4,199,569. Mention is also made of Kitano, U.S. Pat. No. 4,468,390, Beuvry et al., U.S. Pat. No. 5,824,653, EP 0 007 812 A1, U.K. Patent Specification 1 390 336, EP 0 002 916, and Ancare New Zealand Patent No. 237 086, inter alia. Naturally occurring milbemycins are described in Aoki et al., U.S. Pat. No. 3,950,360 as well as in the various references cited in “The Merck Index” 12^(th) ed., S. Budavari, Ed., Merck & Co., Inc. Whitehouse Station, N.J. (1996). Latidectin is described in the “International Nonproprietary Names for Pharmaceutical Substances (INN)”, WHO Drug Information, vol. 17, no. 4, pp. 263-286, (2003). Semisynthetic derivatives of these classes of compounds are well known in the art and are described, for example, in U.S. Pat. Nos. 5,077,308, 4,859,657, 4,963,582, 4,855,317, 4,871,719, 4,874,749, 4,427,663, 4,310,519, 4,199,569, 5,055,596, 4,973,711, 4,978,677, 4,920,148 and EP 0 667 054, all incorporated herein by reference.

In an embodiment, the compositions having an extended shelf-life of the invention comprise at least one avermectin or milbemycin compound in combination with at least one anthelmintic active agent. The avermectin and milbemycin active agents include, but are not limited to, abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, selamectin, milbemectin, milbemycin D, milbemycin oxime, moxidectin or nemadectin, or mixtures of these active agents.

Various types of anthelmintic agents (in addition to one or more macrocyclic lactone) may be used in the compositions of the invention. In some embodiments, the compositions of the invention may include one or more antinematodal agents including, but not limited to, a benzimidazole, an imidazothiazole, a tetrahydropyrimidine, an organophosphate active agent, or mixtures of these active agents. In some embodiments, benzimidazoles including, but not limited to, thiabendazole, cambendazole, parbendazole, oxibendazole, mebendazole, flubendazole, fenbendazole, oxfendazole, albendazole, cyclobendazole, triclabendazole, febantel, thiophanate and its o,o-dimethyl analogue may be included in the compositions.

In other embodiments, the compositions may include an imidazothiazole compounds including, but not limited to, tetramisole, levamisole and butamisole. In still other embodiments, the compositions of the invention may include tetrahydropyrimidine active agents including, but not limited to, pyrantel, oxantel, and morantel.

In still other embodiments, the compositions may include the antinematodal compounds phenothiazine, piperazine as the neutral compound and in various salt forms, diethylcarbamazine, phenols such as disophenol, arsenicals such as arsenamide, ethanolamines such as bephenium, thenium closylate, and methyridine; cyanine dyes including pyrvinium chloride, pyrvinium pamoate and dithiazanine iodide; isothiocyanates including bitoscanate, suramin sodium, phthalofyne, and various natural products including, but not limited to, hygromycin B, α-santonin and kainic acid.

In other embodiments, the compositions of the invention may include antitrematodal agents. Suitable antitrematodal agents include, but are not limited to, the miracils such as miracil D and mirasan; praziquantel, clonazepam and its 3-methyl derivative, oltipraz, lucanthone, hycanthone, oxamniquine, amoscanate, niridazole, nitroxynil, various bisphenol compounds known in the art including hexachlorophene, bithionol, bithionol sulfoxide and menichlopholan; various salicylanilide compounds including tribromsalan, oxyclozanide, clioxanide, rafoxanide, brotianide, bromoxanide and closantel; triclabendazole, diamfenetide, clorsulon, hetolin and emetine. In some embodiments, the compositions of the invention comprise praziquantel.

Anticestodal compounds may also be advantageously used in the compositions of the invention including, but not limited to, arecoline in various salt forms, bunamidine, niclosamide, nitroscanate, paromomycin and paromomycin II.

In certain embodiments, the anthelmintic agent in the compositions of the invention can be a biologically active peptide or protein including, but not limited to, cyclic depsipeptides, which act at the neuromuscular junction by stimulating presynaptic receptors belonging to the secretin receptor family resulting in the paralysis and death of parasites. In one particular embodiment of the cyclic depsipeptide, the depsipeptide is emodepside (see Willson et al., Parasitology, January 2003, 126(Pt 1):79-86). In another embodiment, the cyclic depsipeptide is a compound described in WO 2016/187534 or WO 2017/116702, both incorporated herein by reference.

In another embodiment, anthelmintic compounds of the amino acetonitrile class (AAD) of compounds such as monepantel (ZOLVIX) and the like may be included in the compositions of the invention. These compounds are described, for example, in WO 2004/024704; Sager et al., Veterinary Parasitology, 2009, 159, 49-54; Kaminsky et al., Nature vol. 452, 13 Mar. 2008, 176-181. The compositions of the invention may also include aryloazol-2-yl cyanoethylamino compounds such as those described in US 2008/0312272 to Soll et al. and those described in U.S. patent application Ser. No. 12/618,308, and thioamide derivatives of these compounds, as described in U.S. patent application Ser. No. 12/582,486, filed Oct. 20, 2009, all of which are incorporated herein by reference.

The compositions of the invention may also be combined with paraherquamide compounds and derivatives of these compounds, including derquantel (see Ostlind et al., Research in Veterinary Science, 1990, 48, 260-61; and Ostlind et al., Medical and Veterinary Entomology, 1997, 11, 407-408). The paraherquamide family of compounds are known class of compounds that include a spirodioxepino indole core with activity against certain parasites (see Tet. Lett. 1981, 22, 135; 1 Antibiotics 1990, 43, 1380, and J. Antibiotics 1991, 44, 492). In addition, the structurally related marcfortine family of compounds, such as marcfortines A-C, are also known and may be combined with the formulations of the invention (see J. Chem. Soc.—Chem. Comm. 1980, 601 and Tet. Lett. 1981, 22, 1977). Further references to the paraherquamide derivatives can be found, for example, in WO 91/09961, WO 92/22555, WO 97/03988, WO 01/076370, WO 09/004432, U.S. Pat. Nos. 5,703,078 and 5,750,695, all of which are hereby incorporated by reference in their entirety.

In one embodiment, the invention provides a composition comprising at least one avermectin or milbemycin active agent in combination with at least one of a benzimidazole anthelmintic, an imidazothiazole anthelmintic, a tetrahydropyrimidine anthelmintic, levamisole, pyrantel or praziquantel, in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition comprising at least one of abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, selamectin, milbemectin, milbemycin D, milbemycin oxime, moxidectin or nemadectin; and at least one of a benzimidazole anthelmintic, imidazothiazole anthelmintic, tetrahydropyrimidine anthelmintic, levamisole, pyrantel or praziquantel, together with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition (e.g., spot-on, pour-on) consisting essentially of at least one of abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, selamectin, milbemectin, milbemycin D, milbemycin oxime, moxidectin or nemadectin and at least one of a benzimidazole anthelmintic, imidazothiazole anthelmintic, tetrahydropyrimidine anthelmintic, levamisole, pyrantel or praziquantel, in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition consisting essentially of eprinomectin and praziquantel; in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer.

In another embodiment, the invention provides a composition consisting of eprinomectin and praziquantel; in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer

In another embodiment, the invention provides a topical veterinary composition having an extended shelf-life consisting essentially of about 0.01% (w/v) to about 10% (w/v) eprinomectin; about 1.0% (w/v) to about 30.0% (w/v) praziquantel; about 0.01% (w/v) to about 2.0% (w/v) BHT; about 20% (w/s) to about 35.0% (w/v) glycerol formal; and about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, wherein the composition has a shelf-life of at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months. In yet another embodiment, composition consists essentially of about 0.1% (w/v) to about 5.0% (w/v) eprinomectin; about 5.0% (w/v) to about 15.0% (w/v) praziquantel; about 0.01% (w/v) to about 1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) glycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide. In yet another embodiment, the composition consists essentially of about 0.1% (w/v) to about 1.0% (w/v) eprinomectin; about 8.0% (w/v) to about 12.0% (w/v) praziquantel; about 0.01% (w/v) to about 1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) glycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide.

In yet another embodiment, the invention provides a topical veterinary composition having an extended shelf-life consisting essentially of about 0.01% (w/v) to about 10% (w/v) eprinomectin; about 1.0% (w/v) to about 30.0% (w/v) praziquantel; about 0.01% (w/v) to about 2.0% (w/v) BHT; about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide, wherein the composition has a shelf-life of at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months. In yet another embodiment, composition consists essentially of about 0.1% (w/v) to about 5.0% (w/v) eprinomectin; about 5.0% (w/v) to about 15.0% (w/v) praziquantel; about 0.01% (w/v) to about 1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide. In yet another embodiment, the composition consists essentially of about 0.1% (w/v) to about 1.0% (w/v) eprinomectin; about 8.0% (w/v) to about 12.0% (w/v) praziquantel; about 0.01% (w/v) to about 1.0% (w/v) BHT; about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide. In one embodiment, the glycerol formal is unstabilized by the absence of stabilizers, e.g., EDTA.

In another embodiment, the invention provides a topical veterinary composition having an extended shelf-life for treating or preventing a parasitic infection or infestation in an animal, the composition consisting essentially of about 0.40% (w/v) eprinomectin; about 8.30% (w/v) praziquantel; about 0.10% (w/v) BHT; about 30.38% (w/v) glycerol formal; and QS dimethyl isosorbide. In one embodiment, the glycerol formal is unstabilized by the absence of stabilizers, e.g., EDTA or 2,6-di-tert-butyl-4-methyl phenol.

In another embodiment, the invention provides a topical veterinary composition having an extended shelf-life for treating or preventing a parasitic infection or infestation in an animal, the composition consisting of about 0.40% (w/v) eprinomectin; about 8.30% (w/v) praziquantel; about 0.10% (w/v) BHT; about 30.38% (w/v) glycerol formal; and QS dimethyl isosorbide. In one embodiment, the glycerol formal is unstabilized by the absence of stabilizers, e.g., EDTA or 2,6-di-tert-butyl-4-methyl phenol.

The compositions of the invention, which include two different active agents in a carrier system that is compatible with each active agent, have been surprisingly discovered to be stable, to have an extended shelf-life, and to be effective against a broad spectrum of ectoparasites and/or endoparasites. It will be well apparent to one of skill in the art that combination of two active agents in a single composition without affecting the stability of the active agents during storage or the efficacy of each active upon administration is extremely difficult and unpredictable. The two classes of active agents included in the inventive compositions have substantially different structures and consequently have different solubility and stability requirements. This presents a significant problem when including the multiple active agents in a single formulation, particularly in formulations that require the two active agents to be in solution, such as in spot-on or pour-on formulations. The solubility, log P, molecular weight and other physical characteristics of each active agent in the carrier system affects the ability to deliver the drug into the coat of the animal or to permeate the skin as required. The identification of a suitable carrier system that will solubilize each active agent in a stable solution while being able to deliver the active agents to the targeted location on the animal at the required concentration is a very difficult task and is not predictable or obvious.

Furthermore, the identification of a suitable carrier system to produce a stable, extended shelf-life composition comprising two different classes of active agents is challenging and unobvious.

It is well known in the art that it is very difficult to formulate macrocyclic lactone active agents together with certain other actives due to different carrier requirements and the susceptibility of macrocyclic lactones to degrade in certain solvents. Avermectins and milbemycins are poorly soluble in water and not compatible with acidic conditions, while some anthelmintic agents such as levamisole are more water soluble and require acidic pH for optimum stability (see US 2006/0128641 A1). For example, WO 00/74489 describes liquid compositions comprising a macrocyclic lactone and another anthelmintic (levamisole) where the composition contains separate phases which contain the different active agents in order to meet the different solubility and stability requirements of each active. U.S. Pat. No. 6,489,303 to Jancys et al. describes that mixtures of a macrocyclic lactone and another insoluble anthelmintic agent resulted in an increased rate of degradation of the macrocyclic lactone active agent, requiring the addition of excess antioxidant to stabilize the mixture. Therefore, the combination of two active agents, including a macrocyclic lactone, in a single liquid composition that is both stable for an extended period of time and efficacious against a broad spectrum of ectoparasites and endoparasites represents a significant achievement in the field of veterinary medicine that is not predictable or obvious.

The compositions of the present invention combine active agents that are efficacious against internal and/or external parasites. The compositions of the invention, which in some embodiments are in the form of topical solutions in a homogeneous carrier, are unique in that they achieve excellent long-lasting efficacy against external parasites such as fleas and ticks and/or effectively controlling internal parasites such as Dirofilaria immitis (heartworm), roundworms and other parasitic worms. The compositions of the invention surprisingly achieve the required distribution of an effective amount each different active to the site of the animal required to achieve the superb efficacy against harmful internal and/or external parasites. In particular, the superb efficacy achieved against Dirofilaria immitis (heartworm), roundworms including T. cati, tapeworms including D. caninum, and hookworms including A. tubaeforme is noteworthy and unique.

It is well know that macrocyclic lactone actives and anthelmintic active agents are required to be absorbed into the blood stream to be efficacious against internal parasites. As such, some formulations directed to the treatment and control of endoparasites may contain strong solvents and/or penetration enhancing agents that can disrupt the barrier function of the stratum corneum to allow passage of the actives into the blood stream. Penetration enhancers include compounds with a polar head group and long alkyl chains such as non-ionic surfactants, oleic acid, propylene glycol, decyl methyl sulphoxide and Azone, among others.

In an embodiment of the inventive compositions, the composition will be in the form of a liquid solution or suspension. The pharmaceutically acceptable carrier may be any suitable carrier or diluent commonly used in the formulation art including aqueous or organic solvents or mixtures of solvents. These organic solvents may be found, for example, in Remington Pharmaceutical Sciences, 16^(th) Edition (1986). Organic solvents that can be used in the invention include those described above, and include but are not limited to: acetyltributyl citrate, oleic acid, fatty acid esters such as the dimethyl ester, diisobutyl adipate, diisopropyl adipate (also known as CERAPHYL 230), ketones including acetone, methylisobutyl ketone (MIK) and methyl ethyl ketone and the like, acetonitrile, benzyl alcohol, methanol, ethyl alcohol, isopropanol, butanol, aromatic ethers such as anisole, butyl diglycol, amides including dimethylacetamide and dimethylformamide, dimethyl sulfoxide, ethylene glycol, propylene glycol, glycol ethers including propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, glycol carbonates, monomethylacetamide, dipropylene glycol monomethyl ether, liquid polyoxyethylene glycols (PEG) of different average molecular weight ranges, 2-pyrrolidone including N-methylpyrrolidone, glycerol formal, dimethyl isosorbide, triacetin, C₁-C₁₀ esters of carboxylic acids such as butyl or octyl acetate, benzyl acetate, aryl esters including benzyl benzoate, ethyl benzoate and the like, propylene carbonate, butylene carbonate, and diethyl phthalate, or a mixture of at least two of these solvents.

These solvents can be supplemented by various excipients according to the nature of the desired phases, such as C₈-C₁₀ caprylic/capric triglyceride (ESTASAN or MIGLYOL 812), oleic acid or propylene glycol.

In one embodiment of the invention, the pharmaceutically acceptable carrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof (including acetates, such as ethyl acetate and the like), C₁₀-C₁₈ saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fatty acids or esters thereof, monoesters or diesters of aliphatic diacids, or mixtures thereof.

In some embodiments, the carrier or diluent is a derivative of glycerol including, but not limited to, glycerol monoesters (e.g. monoglycerides), glycerol diesters (e.g. diglycerides), glycerol triesters (e.g. triglycerides such as triacetin), or glycerol formal, or mixtures thereof. Glycerol formal is a mixture of 5-hydroxy-1,3-dioxane and 4-hydroxymethyl-1,3-dioxolane (approximately 60:40), which are cyclic ether compounds derived from glycerol and having 2 oxygen atoms in the ring structure and substituted by alcohol group. Glycerol Formal is a low odor and low toxic solvent for a wide variety of applications in pharmaceutical and cosmetics industry including anti-parasite veterinary formulations.

In another embodiment of the invention, the organic solvents may comprise diisopropyl adipate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 2-pyrrolidone including N-methylpyrrolidone, diethylene glycol monoethyl ether, triacetin, butyl acetate, octyl acetate, propylene carbonate, oleic acid, or a mixture of at least two of these solvents.

In one embodiment, the solvents include C₁-C₁₀ esters of carboxylic acids such as butyl or octyl acetate.

In some embodiments of the invention, the carrier comprises dimethyl isosorbide. Dimethyl Isosorbide (DMI) is a high purity solvent and carrier which offers a safe, effective delivery enhancement mechanism for active ingredients in personal care products and pharmaceutical formulations. In addition dimethyl isosorbide is sometimes used as an epidermal penetration enhancer to provide enhanced penetration of active agents to the epidermis. It may also provide delivery of active agents into the skin while avoiding crystallization of the active agent, which will severely limit the effectiveness of the formulation. Dimethyl Isosorbide is soluble in a variety of ingredients including water, cottonseed oil, isopropanol, isopropyl myristate, propylene glycol, polysorbate 20, and polysorbate 80. It is insoluble in hydrogenated castor oil, lanolin, mineral oils or silicone oil (dimethicone).

In other embodiments, the carrier or diluent can be dimethyl sulfoxide (DMSO), glycol derivatives such as, for example, propylene glycol, glycol ethers, polyethylene glycols or glycerol. As vehicle or diluent, mention may also be made of plant oils such as, but not limited to soybean oil, groundnut oil, castor oil, corn oil, cotton oil, olive oil, grape seed oil, sunflower oil, etc.; mineral oils such as, but not limited to, petrolatum, paraffin, silicone, etc.; aliphatic or cyclic hydrocarbons or alternatively, for example, medium-chain (such as C₈ to C₁₂) triglycerides, or mixtures thereof.

In an embodiment, the carrier or diluent is a mixture of glycerol formal and dimethyl isosorbide. In another embodiment, the glycerol formal is unstabilized by the absence of stabilizers. In yet another embodiment, the glycerol formal is unstablized by the absence of EDTA or 6-di-tert-butyl-4-methyl phenol.

Glycerol formal is commonly available commercially as stabilized glycerol formal by the inclusion of a small amount of stabilizers such as EDTA or 6-di-tert-butyl-4-methyl phenol. In one embodiment of the invention, Applicant surprisingly found that using unstabilized glycerol formal in the formulation, particularly glycerol formal without EDTA or 6-di-tert-butyl-4-methyl phenol, results in a composition having an extended shelf-life, for example, by at least 6 months, at least 12 months, at least 18 months, at least 24 months, at least 36 months, or at least 48 months.

Typically the amount of glycerol formal in the composition is about 20% (w/s) to about 35.0% (w/v), preferably about 25% (w/s) to about 35.0% (w/v) or about 25% (w/s) to about 35.0% (w/v). In an embodiment, glycerol formal is present in the composition at about 30.38% (w/v).

The amount of dimethyl isosorbide in the compositions of the present invention is typically about 50.0% (w/v) to about 75.0% (w/v), preferably about 55.0% (w/v) to about 65.0% (w/v) or about 55.0% (w/v) to about 65.0% (w/v). In an embodiment, dimethyl isosorbide is present in the composition at about 62.82% (w/v) or QS.

The compositions of the invention can be in a variety of forms suitable for different forms of administration including, but are not limited to, oral formulations, injectable formulations, and topical, dermal or subdermal formulations.

In some embodiments the compositions of the invention may be in a form suitable for oral use, for example, as baits (see, e.g., U.S. Pat. No. 4,564,631, incorporated herein by reference), dietary supplements, troches, lozenges, chewables, tablets, hard or soft capsules, emulsions, aqueous or oily suspensions, aqueous or oily solutions, oral drench formulations, dispersible powders or granules, syrups or elixirs, enteric formulations or pastes. Compositions intended for oral use may be prepared according to any method known in the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, bittering agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations.

Tablets may contain the active ingredient in admixture with non-toxic, pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be, for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example, magnesium stearate, stearic acid or talc, the tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the technique described in U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874, which are incorporated herein by reference in their entirety, to form osmotic therapeutic tablets for controlled release.

Formulations for oral use may be hard gelatin capsules, wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. Capsules may also be soft gelatin capsules, wherein the active ingredient is mixed with water or miscible solvents such as propylene glycol, PEGs and ethanol, or an oil medium, for example peanut oil, liquid paraffin, or olive oil.

The compositions of the invention may also be in the form of oil-in-water or water-in-oil emulsions. The oily phase may be a vegetable oil, for example, olive oil or arachis oil, or a mineral oil, for example, liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring phosphatides, for example, soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example, sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide, for example, polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening agents, bittering agents, flavoring agents, and/or preservatives.

In one embodiment of the formulation, the composition of the invention is in the form of a microemulsion. Microemulsions are well suited as the liquid carrier vehicle. Microemulsions are quaternary systems comprising an aqueous phase, an oily phase, a surfactant and a cosurfactant. They are translucent and isotropic liquids. Microemulsions are composed of stable dispersions of microdroplets of the aqueous phase in the oily phase or conversely of microdroplets of the oily phase in the aqueous phase. The size of these microdroplets is less than 200 nm (1000 to 100,000 nm for emulsions). The interfacial film is composed of an alternation of surface-active (SA) and co-surface-active (Co-SA) molecules which, by lowering the interfacial tension, allows the microemulsion to be formed spontaneously.

In one embodiment of the oily phase, the oily phase can be formed from mineral or vegetable oils, from unsaturated polyglycosylated glycerides or from triglycerides, or alternatively from mixtures of such compounds. In one embodiment of the oily phase, the oily phase comprises of triglycerides. In another embodiment of the oily phase, the triglycerides are medium-chain triglycerides, for example C₈-C₁₀ caprylic/capric triglyceride. Another embodiment of the oily phase will represent a % v/v range selected from the group consisting of about 2 to about 15%; about 7 to about 10%; and about 8 to about 9% v/v of the microemulsion.

The aqueous phase includes, for example water or glycol derivatives, such as propylene glycol, glycol ethers, polyethylene glycols or glycerol. In one embodiment of the glycol derivatives, the glycol is selected from the group consisting of propylene glycol, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether and mixtures thereof. Generally, the aqueous phase will represent a proportion from about 1 to about 4% v/v in the microemulsion.

Surfactants for the microemulsion include diethylene glycol monoethyl ether, dipropyelene glycol monomethyl ether, polyglycolyzed C₈-C₁₀ glycerides or polyglyceryl-6 dioleate. In addition to these surfactants, the cosurfactants include short-chain alcohols, such as ethanol and propanol.

Some compounds are common to the three components discussed above, i.e., aqueous phase, surfactant and cosurfactant. However, it is well within the skill level of the practitioner to use different compounds for each component of the same formulation.

Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example, arachis oil, olive oil, sesame oil or coconut oil, or in mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example, beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as sucrose, saccharin or aspartame, bittering agents, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid or other known preservatives.

Aqueous suspensions may contain the active agents in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example, sodium carboxymethylcellulose, methylcellulose, hydroxy-propylmethylcellulose, sodium alginate, polvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example, heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide, with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents and/or bittering agents, such as those set forth above.

Syrups and elixirs may be formulated with sweetening agents, for example, glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, flavoring agent(s) and/or coloring agent(s).

In another embodiment of the invention, the composition can be in paste form. Examples of embodiments in a paste form include but are not limited to those described in U.S. Pat. Nos. 6,787,342 and 7,001,889, both of which are incorporated herein by reference. In addition to the active agent of the invention, the paste can also contain fumed silica; a viscosity modifier; a carrier; optionally, an absorbent; and optionally, a colorant, stabilizer, surfactant, or preservative.

In one embodiment, the process for preparing a paste formulation comprises the steps of:

(a) dissolving or dispersing the active agent into the carrier by mixing;

(b) adding the fumed silica to the carrier containing the dissolved active agent compound and mixing until the silica is dispersed in the carrier;

(c) allowing the intermediate formed in (b) to settle for a time sufficient in order to allow the air entrapped during step (b) to escape; and

(d) adding the viscosity modifier to the intermediate with mixing to produce a uniform paste.

The above steps are illustrative, but not limiting. For example, step (a) can be the last step.

In one embodiment of the formulation, the formulation is a paste containing the active agent compound, fumed silica, a viscosity modifier, an absorbent, a colorant; and a hydrophilic carrier which is a triacetin, a monoglyceride, a diglyceride, or a triglyceride. The paste may also include a viscosity modifier including, but is not limited to, PEG 200, PEG 300, PEG 400, PEG 600, monoethanolamine, triethanolamine, glycerol, propylene glycol, polyoxyethylene (20) sorbitan mono-oleate (polysorbate 80 or Tween 80), or polyoxamers (e.g., Pluronic L 81); an absorbent including, but not limited to, magnesium carbonate, calcium carbonate, starch, or cellulose and its derivatives.

Colorants may be added to the inventive formulations. Colorants contemplated by the present invention are those commonly known in the art. Specific colorants include, for example, dyes, FD&C Blue #1 Aluminum Lake, caramel, colorant based upon iron oxide or a mixture of any of the foregoing. Especially preferred are organic dyes and titanium dioxide. Preferred ranges include from about 0.5% to about 25%.

In some embodiments of the invention, the compositions may be in the form of a sterile injectable solutions or aqueous or oleagenous suspensions. These suspensions may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. Cosolvents such as ethanol, propylene glycol or polyethylene glycols may also be used. Preservatives, such as phenol or benzyl alcohol, may be used.

In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

In one embodiment of the invention, compositions suitable for topical administration to an animal are provided. Topical, dermal and subdermal formulations can include emulsions, creams, ointments, gels, pastes, powders, shampoos, pour-on formulations, ready-to-use formulations, spot-on solutions and suspensions.

In an embodiment, the compositions of the invention are in the form of a spot-on formulation that is applied to a localized area on an animal, rather than the entire coat of the animal or a large portion of the animal's coat. In one embodiment of a localized region, the location is between the shoulders. The spot-on formulation according to the present invention provide long-lasting and broad-spectrum efficacy against ectoparasites and/or endoparasites when the solution is applied to the mammal or bird. The spot-on formulations provide for topical administration of a concentrated solution, suspension, microemulsion or emulsion for intermittent application to a spot on the animal, generally between the two shoulders (solution of spot-on type).

Spot-on formulations are well known techniques for topically delivering an antiparasitic agent to a limited area of the host. For example, U.S. Pat. Nos. 5,045,536 6,426,333; 6,482,425; 6,962,713; and 6,998,131, all incorporated herein by reference, describe spot-on formulations. WO 01/957715, also incorporated herein by reference, describes a method for controlling ectoparasites in small rodents as well as interrupting or preventing the diseases caused by arthropods in small rodents, which comprise applying topical formulations, such as spot-on compositions, to the skin, or hair of the rodents.

For spot-on formulations, the pharmaceutically acceptable carrier may be a liquid carrier vehicle as described herein, and other carriers described in the art, for example in U.S. Pat. No. 6,426,333, which is incorporated herein by reference. In some embodiments, the liquid carrier vehicle can optionally contain a crystallization inhibitor such as the crystallization inhibitors to inhibit the formation of crystals or precipitate of the active components.

The veterinarily acceptable carrier will generally comprise a diluent or vehicle in which the active agents are soluble. It will be apparent to those of skill in the art that the carrier or diluent of the topical compositions must be able to deliver the active agents to the targeted location without the active agents precipitating from solution or forming crystals. In some embodiments, the carrier or diluent of the compositions will be suitable to avoid precipitation or crystallization of the active agents. In other embodiments, the compositions may include a crystallization inhibitor in addition to the carrier or diluent.

In one embodiment of the invention, the carrier for spot-on compositions may comprise diisopropyl adipate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 2-pyrrolidone, N-methylpyrrolidone, diethylene glycol monoethyl ether, triacetin, butyl acetate, octyl acetate, propylene carbonate, oleic acid, or a mixture of at least two of these solvents.

In another embodiment of the invention, the pharmaceutically acceptable carrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof (including acetates, such as ethyl acetate and the like), C₁₀-C₁₈ saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fatty acids or esters thereof, monoesters or diesters of aliphatic diacids, or mixtures thereof.

In yet another embodiment, preferred solvents include C₁-C₁₀ esters of carboxylic acids such as butyl or octyl acetate.

In one embodiment, the compositions of the invention that are suitable for topical administration will comprise glycerol derived carriers including glycerol monoesters (e.g. monoglycerides), glycerol diesters (e.g. diglycerides), glycerol triesters (e.g. triglycerides such as triacetin), glycerol formal, or mixtures thereof.

In another embodiment, the compositions of the invention for topical administration will comprise an alcohol including ethanol or isopropanol; propylene glycol, dimethyl isosorbide (DMI), 2-pyrrolidone, N-methylpyrrolidone, dimethylsulfoxide, glycerol formal, glycol ethers including diethylene glycol monoethyl ether, diethylene glycol monomethyl ether and the like, or mixtures thereof.

In yet another embodiment, the topical compositions of the invention will comprise glycerol formal, dimethyl isosorbide, N-methylpyrrolidone, diethylene glycol monoethyl ether, or mixtures thereof. In still another embodiment, the topical compositions will comprise glycerol formal, dimethyl isosorbide, or a mixture thereof.

Spot-on formulations, described for example in U.S. Pat. No. 7,262,214 (incorporated herein by reference), may be prepared by dissolving the active ingredients into the pharmaceutically or veterinary acceptable vehicle. Alternatively, the spot-on formulation can be prepared by encapsulation of the active ingredients to leave a residue of the therapeutic agent on the surface of the animal. These formulations will vary with regard to the weight of the therapeutic agent in the combination depending on the species of host animal to be treated, the severity and type of infection and the body weight of the host.

Pour-on formulations are described, for example, in U.S. Pat. No. 6,010,710, which is incorporated herein by reference. Some pour-on formulations are advantageously oily, and generally comprise a diluent or vehicle and also a solvent (e.g. an organic solvent) for the active ingredient if the latter is not soluble in the diluent. Other pour-on formulations may be in hydrophilic carriers. Pour-on formulation may be administered to livestock animals such as cattle and sheep. Typically, pour-on formulations are administered to the animal as a stripe to an external surface of the animal, e.g. a stripe from head to tail of the animal. In one embodiment, the process comprises applying the solution to livestock animals before they arrive in the Feed Lot, it being possible for this application to be the final one before the animals are slaughtered.

The compositions of the invention can also be formed in a collar such as those described in U.S. Pat. No. 5,885,607, which is incorporated herein by reference. Within the scope of the invention, matrices usually used to make collars may be used. In one embodiment of the collars which may be mentioned are matrices based on PVC (polyvinyl chloride), as described in U.S. Pat. Nos. 3,318,769; 3,852,416; 4,150,109 and 5,437,869, (all incorporated by reference) and other vinyl polymers.

The plasticizers may be chosen in particular from adipates, phthalates, phosphates and citrates. In another embodiment of the collar, one or more plasticizers are also added to the PVC, these plasticizers being chosen in particular from the following compounds: diethyl phthalate, dioctyl sebacate, dioctyl adipate, diisodecyl phthalate, acetyl tributyl citrate, diethyl hexyl phthalate, di-n-butyl phthalate, benzyl butyl phthalate, acetyl tributyl citrate, tricresyl phosphate, and 2-ethylhexyl diphenyl phosphate.

In another embodiment of the collar, a PVC matrix will be used in the presence of a primary remanent plasticizer and a secondary plasticizer, in particular according to EP 0 539 295 and EP 0 537 998.

Among the secondary plasticizers, mention may be made of the following products: acetyl triethyl citrate, triethyl citrate, triacetin, diethylene glycol monoethyl ether, triphenyl phosphate. A common stabilizer may also be added thereto.

For the purposes of the present invention, the term external device should be understood to refer to any device which can be attached externally to the animal in order to provide the same function as a collar.

Typically the formulations of the invention will comprise about 0.01 to about 10% (w/v) of the macrocyclic lactone active agent(s). More typically, the formulations will contain about 0.01 to about 5% or about 0.01% to about 2% (w/v) of the macrocyclic lactone active agent(s). In some embodiments, the formulations will contain about 0.1 to about 5% or about 0.1 to about 1% (w/v) of the macrocyclic lactone active agent(s). In other embodiments, the formulations will contain about 0.4% (w/v) of the macrocyclic lactone.

The amount of the anthelmintic active agent(s) in the formulations of the invention will typically be from about 1 to about 30% (w/v). More typically, the formulations will contain from about 1 to about 20% (w/v), about 5 to about 15% (w/v) or about 8 to about 12% (w/v). In some embodiments, the formulations will contain about 8.3% (w/v) of the anthelmintic active agent.

In one embodiment, the formulations of the invention will comprise or consist essentially of about 0.01 to about 5% of at least one macrocyclic lactone(s) and about 5 to about 15% (w/v) of at least one anthelmintic active agent(s).

In another embodiment, the compositions of the invention will comprise or consist essentially of about 0.01 to about 5% of eprinomectin and about 5 to about 15% (w/v) of praziquantel, in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetrating enhancer.

In yet another embodiment, the composition will comprise or consist essentially of about 0.4% (w/v) of eprinomectin and about 8.3% (w/v) of praziquantel.

In still another embodiment, the compositions of the invention will comprise or consist essentially of about 0.01 to about 2% (w/v) eprinomectin and about 5 to about 15% (w/v) praziquantel, in combination with about 80 to 95% (w/v) pharmaceutically acceptable carrier or diluent.

In an embodiment, the compositions of the invention comprise or consist essentially of about 0.01 to 2% (w/v) eprinomectin and about 8 to about 12% (w/v) praziquantel, in combination with about 80 to 95% (w/v) pharmaceutically acceptable carrier or diluent. In another embodiment, the pharmaceutically acceptable carrier is a mixture of about 20.0 to about 35.0% (w/v) glycerol formal and about 50.0 to about 75.0% (w/v) dimethyl isosorbide, preferably about 25.0 to about 35.0% (w/v) glycerol formal and about 55.0 to about 65.0% (w/v) dimethyl isosorbide. In yet another embodiment, the glycerol formal is unstabilized by the absence of stabilizers, e.g., EDTA or 6-di-tert-butyl-4-methyl phenol.

In one embodiment, the compositions of the invention will comprise or consist essentially of about 0.4% (w/v) of eprinomectin and about 8.3% (w/v) of praziquantel, in combination with a pharmaceutically acceptable carrier or diluent. In another embodiment, the pharmaceutically acceptable carrier or diluent is glycerol formal, dimethyl isosorbide, or a mixture thereof. In yet another embodiment, the glycerol formal is unstablized by the absence of stabilizers. In yet another embodiment, the glycerol formal is unstabilized by the absence of EDTA or 6-di-tert-butyl-4-methyl phenol.

In an embodiment, the compositions of the invention will comprise or consist essentially of about 0.4% (w/v) of eprinomectin and about 8.3% (w/v) of praziquantel, in combination with a pharmaceutically acceptable carrier or diluent, and optionally an antioxidant and/or a penetration enhancer. In another embodiment, the pharmaceutically acceptable carrier or diluent is glycerol formal, dimethyl isosorbide, or a mixture thereof, and the antioxidant is BHT or BHA. In yet another embodiment, the glycerol formal is unstablized by the absence of stabilizers. In yet another embodiment, the glycerol formal is unstabilized by the absence of EDTA or 6-di-tert-butyl-4-methyl phenol. In one embodiment, the penetration enhancer is propylene glycol.

In one embodiment, the compositions of the invention will comprise or consist essentially of about 0.4% (w/v) of eprinomectin and about 8.3% (w/v) of praziquantel, in combination with about 0.1% (w/v) of the antioxidant, and a pharmaceutically acceptable carrier or diluent. In another embodiment, the pharmaceutically acceptable carrier or diluent is glycerol formal, dimethyl isosorbide, or a mixture thereof, and the antioxidant is BHT or BHA. In yet another embodiment, the glycerol formal is unstablized by the absence of stabilizers. In yet another embodiment, the glycerol formal is unstabilized by the absence of EDTA or 6-di-tert-butyl-4-methyl phenol. In yet another embodiment, the amount of glycerol formal in the compositions is about 30.38% (w/v) and QS of dimethyl isosorbide.

In an embodiment, the compositions of the invention will consist essentially of about 0.4% (w/v) eprinomectin, 8.3% (w/v) praziquantel, 0.1% (w/v) BHT, 30.38% (w/v) unstabilized glycerol formal, and QS or 60.82% (w/v) dimethyl isosorbide.

In one embodiment, the compositions of the invention may consist of eprinomectin, praziquantel, an antioxidant, and a pharmaceutically acceptable carrier or diluent. In another embodiment, the amount of eprinomectin in the compositions is about 0.4% (w/v) and the amount of praziquantel is about 8.3% (w/v). In yet another embodiment, the antioxidant is BHT or BHA and in an amount of about 0.1% (w/v). In yet another embodiment, the pharmaceutically acceptable carrier or diluent is a mixture of 30.38% (w/v) unstabilized glycerol formal, and QS or 60.82% (w/v) dimethyl isosorbide.

In some embodiments of the invention, an emollient and/or spreading and/or film-forming agent may be added to the topical compositions of the invention. In some embodiments the emollient and/or spreading and/or film-forming agents include:

(a) polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinyl acetate and vinylpyrrolidone, polyethylene glycols, benzyl alcohol, mannitol, glycerol, sorbitol, polyoxyethylenated sorbitan esters; lecithin, sodium carboxymethylcellulose, silicone oils, polydiorganosiloxane oils (such as polydimethylsiloxane (PDMS) oils), for example those containing silanol functionalities, or a 45V2 oil,

(b) anionic surfactants such as alkaline stearates, sodium, potassium or ammonium stearates; calcium stearate, triethanolamine stearate; sodium abietate; alkyl sulfates (e.g. sodium lauryl sulfate and sodium cetyl sulfate); sodium dodecylbenzenesulphonate, sodium dioctylsulphosuccinate; fatty acids (e.g. those derived from coconut oil),

(c) cationic surfactants such as water-soluble quaternary ammonium salts of formula N⁺R′R″R′″R″″Y⁻, in which the R radicals are optionally hydroxylated hydrocarbon radicals and Y⁻ is an anion of a strong acid such as the halide, sulfate and sulphonate anions; cetyltrimethylammonium bromide is among the cationic surfactants which can be used,

(d) amine salts of formula N⁺ R′R″R′″ in which the R radicals are optionally hydroxylated hydrocarbon radicals; octadecylamine hydrochloride is among the cationic surfactants which can be used,

(e) nonionic surfactants such as sorbitan esters, which are optionally polyoxyethylenated (e.g. polysorbate 80), polyoxyethylenated alkyl ethers; polyoxypropylated fatty alcohols such as polyoxypropylene-styrol ether; polyethylene glycol stearate, polyoxyethylenated derivatives of castor oil, polyglycerol esters, polyoxyethylenated fatty alcohols, polyoxyethylenated fatty acids, copolymers of ethylene oxide and propylene oxide,

(f) amphoteric surfactants such as the substituted lauryl compounds of betaine, and

(g) a mixture of at least two of these agents.

In one embodiment, the emollient is used in a proportion of from about 0.1 to about 10%, or about 0.25 to about 5% (w/v).

The volume of the topical composition applied is not restricted as long as the amount of substance administered is shown to be safe and efficacious. Typically, the volume applied depends on the size and weight of the animal as well as the concentration of active, the extent of infestation by parasites and the type of administration. For spot-on compositions, the volume applied is typically of the order of about 0.1 to about 1 ml, or about 0.1 ml to about 5 ml, or about 0.1 ml to about 10 ml. In other embodiments, the volume may be about 4 ml to about 7 ml. For larger animals, the volume may be higher including, but not limited to, up to 10 ml, up to 20 ml or up to 30 ml, or higher. In one embodiment of the volume, the volume is on the order of about 0.5 ml to about 1 ml or about 0.5 ml to about 2 ml for cats, and on the order of about 0.3 to about 3 ml or 4 ml for dogs, depending on the weight of the animal. In another embodiment, the volume of the spot-on composition for administration to cats is about 0.3 ml. In another embodiment, the volume is about 0.9 ml.

For the pour-on form of the composition, the volume applied can be of the order of about 0.3 to about 100 mL. In other embodiments, volume applied of the pour-on formulations may be about 1 ml to about 100 ml or about 1 ml to about 50 ml. In still other embodiments, the volume may be about 5 ml to about 50 ml or about 10 ml to about 100 ml.

Dosage forms may contain from about 0.5 mg to about 5 g of a combination of active agents. In one embodiment of the dosage form, the dosage is from about 1 mg to about 500 mg of an active agent, typically about 25 mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 600 mg, about 800 mg, or about 1000 mg.

Methods of Treatment

In another aspect of the invention, a method for preventing or treating a parasite infestation/infection in an animal is provided, comprising administering a composition described herein, for example, a composition comprising an effective amount of at least one macrocyclic lactone active agent in combination with at least one anthelmintic active agent, together with a pharmaceutically acceptable carrier, and optionally an antioxidant and/or a penetration enhancer. The compositions or formulations of the invention have an extended shelf-life and a long-lasting efficacy against endoparasites and/or ectoparasites (e.g. fleas and ticks) that harm animals.

In one embodiment of the invention, methods for the treatment or prevention of a parasitic infestation or infection in a domestic animal are provided, which comprise administering a composition comprising an effective amount of at least one macrocyclic lactone active agent and at least one anthelmintic active agent to the animal. Ectoparasites against which the methods and compositions of the invention are effective include, but are not limited to, fleas, ticks, mites, mosquitoes, flies and lice. The compositions and methods of the invention are also effective against endoparasites including, but not limited to, cestodes, nematodes, such as filariae, Dirofilaria immitis (heartworm), hookworms and roundworms of the digestive tract of animals and humans. In one embodiment, the compositions of the invention are effective for preventing the infection of an animal by Dirofilaria immitis (heartworm) by killing the immature stages of the parasite before they can mature to adult worms.

In one embodiment, the invention provides methods for the treatment and prevention of parasitic infections and infestations of animals (either wild or domesticated), including livestock and companion animals such as cats, dogs, horses, chickens, sheep, goats, pigs, turkeys and cattle, with the aim of ridding these hosts of parasites commonly encountered by such animals.

In an embodiment, the invention provides methods and compositions for the treatment or prevention of parasitic infections and infestations in companion animals including, but not limited to, cats and dogs. In a particularly embodiment of the invention, the methods and compositions described are used to prevent or treat parasitic infections or infestations in cats.

By “treating” or “treat” or “treatment” is intended the application or administration of a composition of the invention to an animal that has a parasitic infestation for the eradication of the parasite or the reduction of the number of the parasites infesting the animal undergoing treatment. In one embodiment, the term “treating” or “treat” is understood to reduce the number of parasites in or on the animal by about at least 70% relative to an untreated control group. In other embodiments, “treating” or “treat” means reducing the number of parasites by at least about 80%, at least about 85% or at least about 90%. In another embodiment, “treating” or “treat” means reducing the number of parasites by at least about 95% or by 100%. It is noted that the compositions of the invention may be used to prevent such a parasitic infestation.

It will be appreciated by those of skill in the art that the methods of the invention encompass administering the macrocyclic lactone active agent(s) and the anthelmintic active agent(s) together in the same carrier or diluent or separately where each active agent or mixtures of the active agents are present in their own carriers or diluents. For example when the active agents are administered topically, the macrocyclic lactone active agent(s) may be administered at the same location on the animal at the same time as the anthelmintic active agent(s), or the macrocyclic lactone active agent(s) may be administered at a different location on the animal than the anthelmintic active agent(s). Each active agent may be administered simultaneously or sequentially in separate carriers, which may be the same or different. Furthermore, each of the active compound(s) may be administered by the same mode of administration (e.g. topical, oral, parenteral, etc.), or the different active agents may be administered by different modes of administration. In an embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

In one embodiment of the invention, the method comprises administering each of the macrocyclic lactone(s) and the anthelmintic(s) separately and sequentially. In another embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

In another embodiment of the invention, the method comprises administering each of the macrocyclic lactone(s) and the anthelmintic(s) simultaneously. In yet another embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

In yet another embodiment of the invention, the method comprises administering each of the macrocyclic lactone(s) and the anthelmintic(s) simultaneously in the same carrier or diluent. In one embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

In still another embodiment, the method comprises administering macrocyclic lactone active agent(s) and the anthelmintic active agent(s) separately in a separate carrier, which may be the same or different for the two active agents. In one embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

In another aspect of the invention, a kit for the treatment or prevention of a parasitic infestation in an animal is provided, which comprises at least one macrocyclic lactone(s) and at least one anthelmintic(s) together with a pharmaceutically acceptable carrier and a dispensing device for topical application of the composition. The dispensing device may be a pipette, syringes, roll on, droppers, capsules, foil packages, vials, twist tip containers and other single dose and multi-dose containers, which includes an effective dose of each active agent in the pharmaceutically acceptable carrier or diluent. In one embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic active agent is praziquantel.

The compositions of the invention may be administered to the animal at different intervals depending on the dose administered. In one embodiment, the compositions of the invention may be administered to the animal monthly. In other embodiments, the compositions may be administered twice a month or even weekly.

Additional Active Agents

Additional veterinary/pharmaceutical active ingredients may be used with the compositions of the invention. In some embodiments, the additional active agents may include, but are not limited to, acaricides, anthelmintics, anti-parasitics and insecticides. Anti-parasitic agents can include both ectoparasiticidal and endoparasiticidal agents.

Veterinary pharmaceutical agents that may be included in the compositions of the invention are well-known in the art (see e.g. Plumb' Veterinary Drug Handbook, 5^(th) Edition, ed. Donald C. Plumb, Blackwell Publishing, (2005) or The Merck Veterinary Manual, 9^(th) Edition, (January 2005)) and include but are not limited to acarbose, acepromazine maleate, acetaminophen, acetazolamide, acetazolamide sodium, acetic acid, acetohydroxamic acid, acetylcysteine, acitretin, acyclovir, albuterol sulfate, alfentanil, allopurinol, alprazolam, altrenogest, amantadine, amikacin sulfate, aminocaproic acid, aminopentamide hydrogen sulfate, aminophylline/theophylline, amiodarone, amitriptyline, amlodipine besylate, ammonium chloride, ammonium molybdenate, amoxicillin, clavulanate potassium, amphotericin B desoxycholate, amphotericin B lipid-based, ampicillin, amprolium, antacids (oral), antivenin, apomorphione, apramycin sulfate, ascorbic acid, asparaginase, aspiring, atenolol, atipamezole, atracurium besylate, atropine sulfate, aurnofin, aurothioglucose, azaperone, azathioprine, azithromycin, baclofen, barbituates, benazepril, betamethasone, bethanechol chloride, bisacodyl, bismuth subsalicylate, bleomycin sulfate, boldenone undecylenate, bromides, bromocriptine mesylate, budenoside, buprenorphine, buspirone, busulfan, butorphanol tartrate, cabergoline, calcitonin salmon, calcitrol, calcium salts, captopril, carbenicillin indanyl sodium, carbimazole, carboplatin, carnitine, carprofen, carvedilol, cefadroxil, cefazolin sodium, cefixime, clorsulon, cefoperazone sodium, cefotaxime sodium, cefotetan disodium, cefoxitin sodium, cefpodoxime proxetil, ceftazidime, ceftiofur sodium, ceftiofur, ceftiaxone sodium, cephalexin, cephalosporins, cephapirin, charcoal (activated), chlorambucil, chloramphenicol, chlordiazepoxide, chlordiazepoxide+/−clidinium bromide, chlorothiazide, chlorpheniramine maleate, chlorpromazine, chlorpropamide, chlortetracycline, chorionic gonadotropin (HCG), chromium, cimetidine, ciprofloxacin, cisapride, cisplatin, citrate salts, clarithromycin, clemastine fumarate, clenbuterol, clindamycin, clofazimine, clomipramine, claonazepam, clonidine, cloprostenol sodium, clorazepate dipotassium, cloxacillin, codeine phosphate, colchicine, corticotropin (ACTH), cosyntropin, cyclophosphamide, cyclosporine, cyproheptadine, cytarabine, dacarbazine, dactinomycin/actinomycin D, dalteparin sodium, danazol, dantrolene sodium, dapsone, decoquinate, deferoxamine mesylate, deracoxib, deslorelin acetate, desmopressin acetate, desoxycorticosterone pivalate, detomidine, dexamethasone, dexpanthenol, dexraazoxane, dextran, diazepam, diazoxide (oral), dichlorphenamide, diclofenac sodium, dicloxacillin, diethylcarbamazine citrate, diethylstilbestrol (DES), difloxacin, digoxin, dihydrotachysterol (DHT), diltiazem, dimenhydrinate, dimercaprol/BAL, dimethyl sulfoxide, dinoprost tromethamine, diphenylhydramine, disopyramide phosphate, dobutamine, docusate/DSS, dolasetron mesylate, domperidone, dopamine, doramectin, doxapram, doxepin, doxorubicin, doxycycline, edetate calcium disodium, calcium EDTA, edrophonium chloride, enalapril/enalaprilat, enoxaparin sodium, enrofloxacin, ephedrine sulfate, epinephrine, epoetin/erythropoietin, eprinomectin, epsiprantel, erythromycin, esmolol, estradiol cypionate, ethacrynic acid/ethacrynate sodium, ethanol (alcohol), etidronate sodium, etodolac, etomidate, euthanasia agents w/pentobarbital, famotidine, fatty acids (essential/omega), felbamate, fentanyl, ferrous sulfate, filgrastim, finasteride, fipronil, florfenicol, fluconazole, flucytosine, fludrocortisone acetate, flumazenil, flumethasone, flunixin meglumine, fluorouracil (5-FU), fluoxetine, fluticasone propionate, fluvoxamine maleate, fomepizole (4-MP), furazolidone, furosemide, gabapentin, gemcitabine, gentamicin sulfate, glimepiride, glipizide, glucagon, glucocorticoid agents, glucosamine/chondroitin sulfate, glutamine, glyburide, glycerine (oral), glycopyrrolate, gonadorelin, grisseofulvin, guaifenesin, halothane, hemoglobin glutamer-200 (OXYGLOBIN®), heparin, hetastarch, hyaluronate sodium, hydrazaline, hydrochlorothiazide, hydrocodone bitartrate, hydrocortisone, hydromorphone, hydroxyurea, hydroxyzine, ifosfamide, imidacloprid, imidocarb dipropinate, impenem-cilastatin sodium, imipramine, inamrinone lactate, insulin, interferon alfa-2a (human recombinant), iodide (sodium/potassium), ipecac (syrup), ipodate sodium, iron dextran, isoflurane, isoproterenol, isotretinoin, isoxsuprine, itraconazole, ivermectin, kaolin/pectin, ketamine, ketoconazole, ketoprofen, ketorolac tromethamine, lactulose, leuprolide, levetiracetam, levothyroxine sodium, lidocaine, lincomycin, liothyronine sodium, lisinopril, lomustine (CCNU), lysine, magnesium, mannitol, marbofloxacin, mechlorethamine, meclizine, meclofenamic acid, medetomidine, medium chain triglycerides, medroxyprogesterone acetate, megestrol acetate, melarsomine, melatonin, meloxican, melphalan, meperidine, mercaptopurine, meropenem, metformin, methadone, methazolamide, methenamine mandelate/hippurate, methimazole, methionine, methocarbamol, methohexital sodium, methotrexate, methoxyflurane, methylene blue, methylphenidate, methylprednisolone, metoclopramide, metoprolol, metronidaxole, mexiletine, mibolerlone, midazolam mineral oil, minocycline, misoprostol, mitotane, mitoxantrone, morphine sulfate, moxidectin, naloxone, mandrolone decanoate, naproxen, narcotic (opiate) agonist analgesics, neomycin sulfate, neostigmine, niacinamide, nitazoxanide, nitenpyram, nitrofurantoin, nitroglycerin, nitroprusside sodium, nizatidine, novobiocin sodium, nystatin, octreotide acetate, olsalazine sodium, omeprozole, ondansetron, opiate antidiarrheals, orbifloxacin, oxacillin sodium, oxazepam, oxibutynin chloride, oxymorphone, oxytretracycline, oxytocin, pamidronate disodium, pancreplipase, pancuronium bromide, paromomycin sulfate, parozetine, pencillamine, general information penicillins, penicillin G, penicillin V potassium, pentazocine, pentobarbital sodium, pentosan polysulfate sodium, pentoxifylline, pergolide mesylate, phenobarbital, phenoxybenzamine, pheylbutazone, phenylephrine, phenypropanolamine, phenytoin sodium, pheromones, parenteral phosphate, phytonadione/vitamin K-1, pimobendan, piperazine, pirlimycin, piroxicam, polysulfated glycosaminoglycan, ponazuril, potassium chloride, pralidoxime chloride, prazosin, prednisolone/prednisone, primidone, procainamide, procarbazine, prochlorperazine, propantheline bromide, Propionibacterium acnes injection, propofol, propranolol, protamine sulfate, pseudoephedrine, psyllium hydrophilic mucilloid, pyridostigmine bromide, pyrilamine maleate, pyrimethamine, quinacrine, quinidine, ranitidine, rifampin, s-adenosyl-methionine (SAMe), saline/hyperosmotic laxative, selamectin, selegiline/l-deprenyl, sertraline, sevelamer, sevoflurane, silymarin/milk thistle, sodium bicarbonate, sodium polystyrene sulfonate, sodium stibogluconate, sodium sulfate, sodum thiosulfate, somatotropin, sotalol, spectinomycin, spironolactone, stanozolol, streptokinase, streptozocin, succimer, succinylcholine chloride, sucralfate, sufentanil citrate, sulfachlorpyridazine sodium, sulfadiazine/trimethroprim, sulfamethoxazole/trimethoprim, sulfadimentoxine, sulfadimethoxine/ormetoprim, sulfasalazine, taurine, tepoxaline, terbinafline, terbutaline sulfate, testosterone, tetracycline, thiacetarsamide sodium, thiamine, thioguanine, thiopental sodium, thiotepa, thyrotropin, tiamulin, ticarcilin disodium, tiletamine/zolazepam, tilmocsin, tiopronin, tobramycin sulfate, tocainide, tolazoline, telfenamic acid, topiramate, tramadol, trimcinolone acetonide, trientine, trilostane, trimepraxine tartrate w/prednisolone, tripelennamine, tylosin, urdosiol, valproic acid, vanadium, vancomycin, vasopressin, vecuronium bromide, verapamil, vinblastine sulfate, vincristine sulfate, vitamin E/selenium, warfarin sodium, xylazine, yohimbine, zafirlukast, zidovudine (AZT), zinc acetate/zinc sulfate, zonisamide and mixtures thereof.

In yet another embodiment of the invention, additional adulticide insecticides and acaricides can also be added to the composition of the invention. These include pyrethrins (which include cinerin I, cinerin II, jasmolin I, jasmolin II, pyrethrin I, pyrethrin II and mixtures thereof) and pyrethroids, and carbamates (which include but are not limited to benomyl, carbanolate, carbaryl, carbofuran, meththiocarb, metolcarb, promacyl, propoxur, aldicarb, butocarboxim, oxamyl, thiocarboxime and thiofanox).

Suitable organophosphate active agents include, but are not limited to, coumaphos, trichlorfon, haloxon, naftalofos and dichlorvos, heptenophos, mevinphos, monocrotophos, TEPP, tetrachlorvinphos, and arylpyrazoles, e.g., fipronil.

In another embodiment of the invention, nodulisporic acid and its derivatives (a class of known acaricidal, anthelmintic, anti-parasitic and insecticidal agents) may be included in the compositions of the invention. These compounds are used to treat or prevent infections in humans and animals and are described, for example, in U.S. Pat. Nos. 5,399,582, 5,962,499, 6,221,894 and 6,399,786, all of which are hereby incorporated by reference in their entirety. The compositions may include one or more of the known nodulisporic acid derivatives in the art, including all stereoisomers, such as those described in the literature cited above.

In yet other embodiments, the compositions of the invention may include other active agents that are effective against arthropod parasites. Suitable active agents include, but are not limited to, bromocyclen, chlordane, DDT, endosulfan, lindane, methoxychlor, toxaphene, bromophos, bromophos-ethyl, carbophenothion, chlorfenvinphos, chlorpyrifos, crotoxyphos, cythioate, diazinon, dichlorenthion, diemthoate, dioxathion, ethion, famphur, fenitrothion, fenthion, fospirate, iodofenphos, malathion, naled, phosalone, phosmet, phoxim, propetamphos, ronnel, stirofos, allethrin, cyhalothrin, cypermethrin, deltamethrin, fenvalerate, flucythrinate, permethrin, phenothrin, pyrethrins, resmethrin, benzyl benzoate, carbon disulfide, crotamiton, diflubenzuron, diphenylamine, disulfiram, isobornyl thiocyanato acetate, monosulfiram, pirenonylbutoxide, rotenone, triphenyltin acetate, triphenyltin hydroxide, deet, dimethyl phthalate, and the compounds 1,5a,6,9,9a,9b-hexahydro-4a(4H)-dibenzofurancarboxaldehyde (MGK-11), 2-(2-ethylhexyl)-3a,4,7,7a-tetrahydro-4,7-methano-1H-isoindole-1,3 (2H)dione (MGK-264), dipropyl-2,5-pyridinedicarboxylate (MGK-326) and 2-(octylthio)ethanol (MGK-874).

In another embodiment, the compositions of the invention may advantageously include one or more compounds of the isoxazoline class of compounds. These active agents are described in WO 2007/079162, WO 2007/075459 and US 2009/0133319, WO 2007/070606 and US 2009/0143410, WO 2009/003075, WO 2009/002809, WO 2009/024541, WO 2005/085216, U.S. Pat. Nos. 8,466,115, 8,853,186, 8,383,659 and US 2007/0066617 and WO 2008/122375, all of which are incorporated herein by reference in their entirety.

An insecticidal agent that can be combined with the compound of the invention to form a composition can be a substituted pyridylmethyl derivative compound such as imidacloprid. Agents of this class are described above, and for example, in U.S. Pat. No. 4,742,060 or in EP 0 892 060. It would be well within the skill level of the practitioner to decide which individual compound can be used in the inventive formulation to treat a particular infection of an insect.

In certain embodiments, an insecticidal agent that can be combined with the compositions of the invention is a semicarbazone, such as metaflumizone.

In general, the additional active agent is included in the composition in an amount of between about 0.1 μg and about 1000 mg. More typically, the additional active agent may be included in a dose of about 10 μg to about 500 mg, about 1 mg to about 300 mg, about 10 mg to about 200 mg or about 10 mg to about 100 mg. In one embodiment of the invention, the additional active agent is included in a dose of between about 1 μg and about 10 mg. In other embodiments of the invention, the additional active agent may be included in a dose of about 5 μg/kg to about 50 mg/kg per weight of the animal. In other embodiments, the additional active agent may be present in a dose of about 0.01 mg/kg to about 30 mg/kg, about 0.1 mg/kg to about 20 mg/kg, or about 0.1 mg/kg to about 10 mg/kg of weight of animal. In other embodiments, the additional active agent may be present in a dose of about 5 μg/kg to about 200 μg/kg or about 0.1 mg/kg to about 1 mg/kg of weight of animal. In still another embodiment of the invention, the additional active agent is included in a dose between about 0.5 mg/kg to about 50 mg/kg.

Optionally, a fragrance may be added to any of the compositions of the invention. Fragrances which are useful for the invention include but are not limited to:

(i) carboxylic acid esters such as octyl acetate, isoamyl acetate, isopropyl acetate and isobutyl acetate;

(ii) fragrant oils such as lavender oil.

The compositions of the invention are made by mixing the appropriate amount of the active agents, pharmaceutically acceptable carrier or diluent and optionally a crystallization inhibitor, antioxidant, preservative, film former, etc., to form a composition of the invention. Various forms (e.g. tablets, pastes, pour-on, spot-on, collars, etc.) of the composition can be obtained by following the method of making these forms described above by the description of making these forms found in general formulation text known to those in the art, e.g. Remington—The Science and Practice of Pharmacy (21^(st) Edition) (2005), Goodman & Gilman's The Pharmacological Basis of Therapeutics (11^(th) Edition) (2005) and Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems (8^(th) Edition), edited by Allen et al., Lippincott Williams & Wilkins, (2005).

The inventive formulations may contain other inert ingredients such as antioxidants, preservatives, or pH stabilizers. These compounds are well known in the formulation art. Antioxidant such as an alpha tocopherol, ascorbic acid, ascrobyl palmitate, fumaric acid, malic acid, sodium ascorbate, sodium metabisulfate, n-propyl gallate, BHA (butylated hydroxy anisole), BHT (butylated hydroxy toluene) monothioglycerol and the like, may be added to the present formulation. The antioxidants are generally added to the formulation in amounts of from about 0.01 to about 2.0% (w/v), with about 0.05 to about 1.0% (w/v) being especially preferred, and about 0.10% (w/v) being most preferred. In some embodiments, the formulations contain an antioxidant. In one embodiment, the antioxidant is BHT. In another embodiment, the antioxidant is BHA.

Preservatives, such as the parabens (methylparaben and/or propylparaben), are suitably used in the formulation in amounts ranging from about 0.01 to about 2.0%, with about 0.05 to about 1.0% being especially preferred. Other preservatives include benzalkonium chloride, benzethonium chloride, benzoic acid, benzyl alcohol, bronopol, butylparaben, cetrimide, chlorhexidine, chlorobutanol, chlorocresol, cresol, ethylparaben, imidurea, methylparaben, phenol, phenoxyethanol, phenylethyl alcohol, phenylmercuric acetate, phenylmercuric borate, phenylmercuric nitrate, potassium sorbate, sodium benzoate, sodium propionate, sorbic acid, thimerosal, and the like. Preferred ranges for these compounds include from about 0.01 to about 5%.

Compounds which stabilize the pH of the formulation are also contemplated. Again, such compounds are well known to a practitioner in the art as well as how to use these compounds. Buffering systems include, for example, systems selected from the group consisting of acetic acid/acetate, malic acid/malate, citric acid/citrate, tataric acid/tartrate, lactic acid/lactate, phosphoric acid/phosphate, glycine/glycimate, tris, glutamic acid/glutamates and sodium carbonate.

The compositions of the invention are administered in parasiticidally effective amounts which are determined by the route of administration, e.g. oral, parenteral, topical, etc. In each aspect of the invention, the compounds and compositions of the invention can be applied against a single pest or combinations thereof.

The compositions of the invention may be administered continuously, for treatment or prevention of parasitic infections or infestations. In this manner, the compositions of the invention deliver an effective amount of the active compounds to the animal in need thereof to control the target parasites. By “effective amount” is intended a sufficient amount of a composition of the invention to eradicate or reduce the number of parasites infesting the animal. In some embodiments, an effective amount of the active agent achieves at least 70% efficacy against the target parasite. In other embodiments, an effective amount of the active agent achieves at least 80%, or at least 90% efficacy against the target pests. Preferably, an effective amount of the active agent will achieve at least 95%, at least 98% or 100% efficacy against the target parasites.

Generally, a dose of from about 0.001 to about 100 mg per kg of body weight given as a single dose or in divided doses for a period of from 1 to 5 days will be satisfactory but, of course, there can be instances where higher or lower dosage ranges are indicated, and such are within the scope of this invention. It is well within the routine skill of the practitioner to determine a particular dosing regimen for a specific host and parasite.

In one treatment embodiment, the treatment is carried out so as to administer to the animal, on a single occasion, a dose containing between about 0.001 and about 100 mg/kg of the active agents. In another embodiment, the composition administered delivers a dose of about 0.01 to 5 mg/kg of a macrocyclic lactone active agent and about 1 to 20 mg/kg of an anthelmintic compound. In another embodiment, the compositions of the invention will deliver about 0.1 to 1 mg/kg of a macrocyclic lactone and about 5 to about 15 mg/kg of an anthelmintic compound. In another embodiment, the compositions of the invention will deliver about 0.5 mg/kg of a macrocyclic lactone and about 10 mg/kg of an anthelmintic compound. In yet another embodiment, the macrocyclic lactone active agent is eprinomectin and the anthelmintic compound is praziquantel.

Higher amounts may be provided for very prolonged release in or on the body of the animal. In another treatment embodiment, the amount of active agents for birds and other animals which are small in size is greater than about 0.01 mg/kg, and in another embodiment for the treatment of small-sized birds and other animals, the amount of is between about 0.01 and about 20 mg/kg of weight of animal.

The solutions according to the invention may be applied using any means known per se, e.g. using an applicator gun or a metering flask, pipette, syringes, roll on, droppers, capsules, foil packages, vials, twist tip containers and other single dose and multi-dose containers,

In yet another embodiment for the treatment of cats, a composition of the invention comprising or consisting essentially of a macrocyclic lactone and an anthelmintic compound has an efficacy of at least about 70%, 80%, 85%, 90%, 95% or 100% against endoparasites including Dipylidium caninum and Taenia taeniaeformis. In another embodiment for the treatment of cats, a composition of the invention has an efficacy of about 70%, 80%, 85%, at least 90%, at least 95% or 100% against Taenia taeniaeformis. In another embodiment for the treatment of cats, a composition of the invention has an efficacy of about 70%, 80%, 85%, at least 90%, at least 95% or 100% against Echinococcus multilocularis. In one embodiment, the macrocyclic lactone is eprinomectin and the anthelmintic compound is praziquantel.

In another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of greater than about 95%, greater than about 97% or greater than about 99% against adult Dipylidium caninum wherein the efficacy is statistically significant with a p<0.008.

In another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of 100% against adult Echinococcus multilocularis wherein the efficacy is statistically significant with a p<0.001.

In another embodiment for the treatment of cats, a composition comprising or consisting essentially of a macrocyclic lactone and an anthelmintic compound has an efficacy of at least about 70%, 80%, 85%, at least 90%, at least 95% or 100% against Toxocara cati (roundworm). In one embodiment, the macrocyclic lactone is eprinomectin and the anthelmintic compound is praziquantel. In another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of greater than about 98% or greater than about 99% against Toxocara cati wherein the efficacy is statistically significant with a p<0.001. In yet another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of greater than about 98% or greater than about 99% against the L4 Luminal larvae stage of Toxocara cati wherein the efficacy is statistically significant with a p<0.001.

In another embodiment for the treatment of cats, a composition of the invention comprising or consisting essentially of a macrocyclic lactone and an anthelmintic compound has an efficacy of at least about 70%, 80%, 85%, at least 90%, at least 95% or 100% against Ancylostoma tubaeforme Ancylostoma braziliense (hookworm). In one embodiment, the macrocyclic lactone is eprinomectin and the anthelmintic compound is praziquantel. In another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of greater than about 98% or greater than about 99% against Ancylostoma tubaeforme or Ancylostoma braziliense wherein the efficacy is statistically significant with a p<0.001. In yet another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of greater than about 85%, greater than about 90%, greater than about 95% or greater than about 99% against the L4 larvae stage of Ancylostoma tubaeforme wherein the efficacy is statistically significant with a p<0.001. In yet another embodiment for the treatment of cats, a composition comprising or consisting essentially of eprinomectin and praziquantel has an efficacy of 100% against the L4 larvae stage of Ancylostoma tubaeforme wherein the efficacy is statistically significant with a p<0.001.

In another embodiment for the treatment of cats, a composition of the invention comprising or consisting essentially of a macrocyclic lactone and an anthelmintic compound has an efficacy of 100% against Dirofilaria immitis (heartworm). In one embodiment, the macrocyclic lactone is eprinomectin and the anthelmintic compound is praziquantel. In another embodiment for the treatment of cats, a composition of the invention comprising or consisting essentially of eprinomectin and praziquantel is found to have an efficacy of 100% against different isolates of Dirofilaria immitis (heartworm) from the U.S. and Europe.

In another embodiment for the treatment of cats, a composition of the invention comprising or consisting essentially of a macrocyclic lactone and an anthelmintic compound has proven safe for use in cats with adult Dirofilaria immitis (heartworm) infection. In one embodiment, the macrocyclic lactone is eprinomectin and the anthelmintic compound is praziquantel.

In one embodiment of the location of administration, a single formulation containing the active agent in a substantially liquid carrier and in a form which makes possible a single application, or an application repeated a small number of times, will be administered to the animal over a localized region of the animal, e.g. between the two shoulders. In one embodiment of the invention, the localized region has a surface area of about 10 cm² or larger. In another embodiment of the invention, the localized region has a surface are of between about 5 and about 10 cm² area.

EXAMPLES

The invention is further described by the following non-limiting examples which further illustrate the invention, and are not intended, nor should they be interpreted to, limit the scope of the invention.

Example 1: Exemplified Formulation

A composition of the present invention was formulated as a topical formulation with the specifics shown below in Table 1.

Concentration Concentration Ingredient (% w/v) (% w/w) Function Praziquantel 8.300 7.032 Active Ingredient Eprinomectin 0.4000 0.3389 Active Ingredient BHT, NF 0.1000 0.08472 Antioxidant Glycerol Formal 30.38 25.74 Solvent (unstabilized) DMI QS 66.81 (QS) Solvent

Relative Density at 20° C.=1.1803 Example 2: Efficacy Against Endoparasites

The efficacy of topical compositions comprising eprinomectin and praziquantel in a pharmaceutically acceptable carrier (mixture of glycerol formal and dimethyl isosorbide) against endoparasites is studied at different concentrations to deliver different doses of eprinomectin and praziquantel.

Cats are infected with infective materials (eggs, larvae) of the target parasite before treatment. Cats are screened and selected for the study based on positive target parasite diagnosis (e.g. egg identification in feces). Alternatively, cats positive for the target parasite are sourced and confirmed to be infected with the parasite (e.g. egg identification in feces). On day 0, cats are treated with the composition tested, except for the control group. On approximately day 7-10 (time necessary for parasite to die and to be eliminated from the body), cats are necropsied for parasite recovery and count. The efficacy or percentage reduction of the treatment is calculated by comparing the mean number of live target parasites in the treated group with the mean number of live target parasites in the control group.

Compositions comprising praziquantel to deliver doses of 6, 8 or 10 mg/kg are tested against Dipylidium caninum in 3 studies. The efficacy of compositions comprising praziquantel is tested against T. taeniaeformis and T. cati at certain doses. The data shows that at a dose of 10 mg/kg praziquantel and 2.5 mg/kg eprinomectin, there is a 92-100% reduction in the number of live Dipylidium caninum and T. taeniaeformis. At a dose of 10 mg/kg praziquantel and 0.25 mg/kg eprinomectin, there is a 95-100% reduction in the number of live Dipylidium caninum and T call.

Example 3: Effect of Eprinomectin Dose Against Endoparasites

In 12 separate studies, the effectiveness of compositions comprising praziquantel and varying doses of eprinomectin against various endoparasites is studied. The compositions contain a concentration of praziquantel to deliver a dose of 10 mg/kg. The concentration of eprinomectin was can be varied to deliver doses of between 0.1 mg/kg to 10 mg/kg. Cats infected naturally or experimentally with A. tubaeforme (hookworm), T. cati (roundworm), D. caninum and different strains of D. immitis (heartworm) are used in the study. The results show that at a dose of 0.2 mg/kg to 10 mg/kg eprinomectin, there is a 92-100% reduction in the number of live T. cati and a 98-100% reduction in the number of live A. tubaeforme.

Example 4: Efficacy Against Endoparasites at 0.5 mg/kg Eprinomectin and 10 mg/kg Praziquantel

The efficacy of topical formulation in Example 1 comprising eprinomectin and praziquantel in a pharmaceutically acceptable carrier (mixture of glycerol formal and dimethyl isosorbide) against endoparasites is studied at a dose of 0.5 mg/kg eprinomectin and 10 mg/kg praziquantel.

Cats are infected with infective materials (eggs, larvae) of the target parasite before treatment. Cats are screened and selected for the study based on positive target parasite diagnosis (e.g. egg identification in feces). Alternatively, cats positive for the target parasite are sourced and confirmed to be infected with the parasite (e.g. egg identification in feces). On day 0, cats are treated with the composition tested, except for the control group. On approximately day 7-10 (time necessary for parasite to die and to be eliminated from the body), cats are necropsied for parasite recovery and count. The efficacy or percentage reduction of the treatment is calculated by comparing the mean number of live target parasites in the treated group with the mean number of live target parasites in the control group.

The formulation of Example 1 at 0.5 mg/kg eprinomectin and 10 mg/kg praziquantel is tested against Dipylidium caninum, T. taeniaeformis and T. cati. The data shows a 92-100% reduction in the number of live Dipylidium caninum, T. cali and T. taeniaeformis.

Example 5: Stability Study of Cat Endoparasiticide (Eprinomectin 0.4% (w/v) and Praziquantel 8.3% (w/v) Topical Solution in the Market Container

This experiment demonstrates the superior stability exhibited by the formulation of Example 1. The stability of each active in a preferred composition of the invention comprising eprinomectin and praziquantel in a carrier comprising glycerol formal and dimethyl isosorbide was evaluated at accelerated condition (30° C./65% Relative Humidity) using high performance liquid chromatography (HPLC). The study demonstrated that each active in the composition was stable in solution for up to at least 18 months at 30° C./65% RH in the presence of each other.

Table 2 below shows the average % label claim of praziquantel and eprinomectin from two different HPLC runs at different time point in month, from 0 to 18 months.

Time point (month) 0 3 6 9 12 18 Praziquantel (% LC) 99.52 97.38 97.74 98.44 98.36 97.04 Eprinomectin (% LC) 99.33 97.92 97.61 98.40 98.50 96.48 These data demonstrate the superior shelf-life of the inventive formulation.

Example 6: Pharmacokinetic Assessment

The formulation of Example 1 was administered to cats and the distribution of the two active agents was measured. The concentration of eprinomectin and praziquantel in the blood of cats over time is depicted in FIG. 1. After administration, the formulation spreads across the skin and the active agents are rapidly absorbed. The Cmax of eprinomectin is reached in 24 hours and the Cmax of praziquantel is reached in 6 hours. The terminal half-life of praziquantel is measured to be 3.08 days and the half-life of eprinomectin is measured to be 4.75 days.

As the non-limiting examples above demonstrate, the stable, extended shelf-life compositions of the invention comprising at least one macrocyclic lactone and at least one anthelmintic compound show superior long lasting efficacy against both ectoparasites and endoparasites in a mammal (e.g., a cat).

Having thus described in detail various embodiments of the present invention, it is to be understood that the invention defined by the above paragraphs is not to be limited to particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope of the present invention. 

What is claimed is:
 1. A topical veterinary composition for treating or preventing a parasitic infection or infestation in an animal comprising: (a) a combination of at least one macrocyclic lactone active agent and at least one anthelmintic active agent; (b) a pharmaceutically acceptable carrier; and (c) optionally an antioxidant.
 2. A topical veterinary composition having an extended shelf-life for treating or preventing a parasitic infection or infestation in an animal, the composition consisting essentially of: (a) about 0.01% (w/v) to about 10% (w/v) eprinomectin; (b) about 1.0% (w/v) to about 30.0% (w/v) praziquantel; (c) about 0.01% (w/v) to about 2.0% (w/v) BHT; (d) about 20% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and (e) about 50.0% (w/v) to about 75.0% (w/v) dimethyl isosorbide; wherein the composition has a shelf-life of at least 6 months.
 3. The topical veterinary composition of claim 2, wherein the composition consists essentially of: (a) about 0.1% (w/v) to about 5.0% (w/v) eprinomectin; (b) about 5.0% (w/v) to about 15.0% (w/v) praziquantel; (c) about 0.01% (w/v) to about 1.0% (w/v) BHT; (d) about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and (e) about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide.
 4. The topical veterinary composition of claim 2, wherein the composition consists essentially of: (a) about 0.1% (w/v) to about 1.0% (w/v) eprinomectin; (b) about 8.0% (w/v) to about 12.0% (w/v) praziquantel; (c) about 0.01% (w/v) to about 1.0% (w/v) BHT; (d) about 25% (w/s) to about 35.0% (w/v) unstabilized glycerol formal; and (e) about 55.0% (w/v) to about 65.0% (w/v) dimethyl isosorbide.
 5. A topical veterinary composition having an extended shelf-life for treating or preventing a parasitic infection or infestation in an animal, the composition consisting essentially of: (a) about 0.40% (w/v) eprinomectin; (b) about 8.30% (w/v) praziquantel; (c) about 0.10% (w/v) BHT; (d) about 30.38% (w/v) unstabilized glycerol formal; and (e) QS dimethyl isosorbide, wherein the composition has a shelf-life of at least 6 months.
 6. The topical veterinary composition of any one of claims 2 to 5, wherein the composition is in the form of a spot-on or a pour-on formulation.
 7. A method for the treatment or prevention of a parasitic infestation or infection in an animal comprising administering to the animal in need thereof an effective amount of the topical veterinary composition of any one of claims 2 to
 6. 8. The method of claim 7, wherein the parasite is an endoparasite.
 9. The topical veterinary composition of claim 1, wherein the at least one macrocyclic lactone active agent is eprinomectin.
 10. The topical veterinary composition of claim 1, wherein the at least one anthelmintic active agent is praziquantel.
 11. The topical veterinary composition of claim 1, wherein the pharmaceutically acceptable carrier comprises non-stabilized glycerol formal, dimethyl isosorbide, or a mixture thereof.
 12. The topical veterinary composition of claim 1, wherein the antioxidant is BHT.
 13. A method for the treatment or prevention of a parasitic infestation or infection in an animal comprising administering to the animal in need thereof an effective amount of the topical veterinary composition of claim
 1. 14. The method of claim 8, wherein the endoparasite comprises cestodes, nematodes, and/or trematodes. 